Initial commit of the Faster IT roundcube_calendar plugin distribution

This includes:
 * Kolab plugins 3.2.9 (calendar and libcalendaring)
 * CalDAV driver 3.2.8
 * .htaccess files for at least some security
 * SabreDAV updated to 1.8.12 (Jan 2015 release)
 * Support for CURLOPT_SSL_* settings to allow self-signed certificates
 * Small fixes & improved documentation

181 files changed, 26001 insertions, 0 deletions

diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/AbstractBackend.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/AbstractBackend.php
new file mode 100644
index 0000000..2586441
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/AbstractBackend.php
@@ -0,0 +1,155 @@
+<?php
+
+namespace OldSabre\CalDAV\Backend;
+
+use OldSabre\VObject;
+use OldSabre\CalDAV;
+
+/**
+ * Abstract Calendaring backend. Extend this class to create your own backends.
+ *
+ * Checkout the BackendInterface for all the methods that must be implemented.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractBackend implements BackendInterface {
+
+    /**
+     * Updates properties for a calendar.
+     *
+     * The mutations array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param mixed $calendarId
+     * @param array $mutations
+     * @return bool|array
+     */
+    public function updateCalendar($calendarId, array $mutations) {
+
+        return false;
+
+    }
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by \OldSabre\CalDAV\CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
+     *
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
+     *
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on either VEVENT or VTODO.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in \OldSabre\CalDAV\CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * @param mixed $calendarId
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery($calendarId, array $filters) {
+
+        $result = array();
+        $objects = $this->getCalendarObjects($calendarId);
+
+        $validator = new \OldSabre\CalDAV\CalendarQueryValidator();
+
+        foreach($objects as $object) {
+
+            if ($this->validateFilterForObject($object, $filters)) {
+                $result[] = $object['uri'];
+            }
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * This method validates if a filters (as passed to calendarQuery) matches
+     * the given object.
+     *
+     * @param array $object
+     * @param array $filters
+     * @return bool
+     */
+    protected function validateFilterForObject(array $object, array $filters) {
+
+        // Unfortunately, setting the 'calendardata' here is optional. If
+        // it was excluded, we actually need another call to get this as
+        // well.
+        if (!isset($object['calendardata'])) {
+            $object = $this->getCalendarObject($object['calendarid'], $object['uri']);
+        }
+
+        $data = is_resource($object['calendardata'])?stream_get_contents($object['calendardata']):$object['calendardata'];
+        $vObject = VObject\Reader::read($data);
+
+        $validator = new CalDAV\CalendarQueryValidator();
+        return $validator->validate($vObject, $filters);
+
+    }
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/BackendInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/BackendInterface.php
new file mode 100644
index 0000000..81f7778
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/BackendInterface.php
@@ -0,0 +1,233 @@
+<?php
+
+namespace OldSabre\CalDAV\Backend;
+
+/**
+ * Every CalDAV backend must at least implement this interface.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface BackendInterface {
+
+    /**
+     * Returns a list of calendars for a principal.
+     *
+     * Every project is an array with the following keys:
+     *  * id, a unique id that will be used by other functions to modify the
+     *    calendar. This can be the same as the uri or a database key.
+     *  * uri, which the basename of the uri with which the calendar is
+     *    accessed.
+     *  * principaluri. The owner of the calendar. Almost always the same as
+     *    principalUri passed to this method.
+     *
+     * Furthermore it can contain webdav properties in clark notation. A very
+     * common one is '{DAV:}displayname'.
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getCalendarsForUser($principalUri);
+
+    /**
+     * Creates a new calendar for a principal.
+     *
+     * If the creation was a success, an id must be returned that can be used to reference
+     * this calendar in other methods, such as updateCalendar.
+     *
+     * @param string $principalUri
+     * @param string $calendarUri
+     * @param array $properties
+     * @return void
+     */
+    public function createCalendar($principalUri,$calendarUri,array $properties);
+
+    /**
+     * Updates properties for a calendar.
+     *
+     * The mutations array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param mixed $calendarId
+     * @param array $mutations
+     * @return bool|array
+     */
+    public function updateCalendar($calendarId, array $mutations);
+
+    /**
+     * Delete a calendar and all it's objects
+     *
+     * @param mixed $calendarId
+     * @return void
+     */
+    public function deleteCalendar($calendarId);
+
+    /**
+     * Returns all calendar objects within a calendar.
+     *
+     * Every item contains an array with the following keys:
+     *   * id - unique identifier which will be used for subsequent updates
+     *   * calendardata - The iCalendar-compatible calendar data
+     *   * uri - a unique key which will be used to construct the uri. This can be any arbitrary string.
+     *   * lastmodified - a timestamp of the last modification time
+     *   * etag - An arbitrary string, surrounded by double-quotes. (e.g.:
+     *   '  "abcdef"')
+     *   * calendarid - The calendarid as it was passed to this function.
+     *   * size - The size of the calendar objects, in bytes.
+     *
+     * Note that the etag is optional, but it's highly encouraged to return for
+     * speed reasons.
+     *
+     * The calendardata is also optional. If it's not returned
+     * 'getCalendarObject' will be called later, which *is* expected to return
+     * calendardata.
+     *
+     * If neither etag or size are specified, the calendardata will be
+     * used/fetched to determine these numbers. If both are specified the
+     * amount of times this is needed is reduced by a great degree.
+     *
+     * @param mixed $calendarId
+     * @return array
+     */
+    public function getCalendarObjects($calendarId);
+
+    /**
+     * Returns information from a single calendar object, based on it's object
+     * uri.
+     *
+     * The returned array must have the same keys as getCalendarObjects. The
+     * 'calendardata' object is required here though, while it's not required
+     * for getCalendarObjects.
+     *
+     * This method must return null if the object did not exist.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @return array|null
+     */
+    public function getCalendarObject($calendarId,$objectUri);
+
+    /**
+     * Creates a new calendar object.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function createCalendarObject($calendarId,$objectUri,$calendarData);
+
+    /**
+     * Updates an existing calendarobject, based on it's uri.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function updateCalendarObject($calendarId,$objectUri,$calendarData);
+
+    /**
+     * Deletes an existing calendar object.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @return void
+     */
+    public function deleteCalendarObject($calendarId,$objectUri);
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by OldSabre\CalDAV\CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
+     *
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
+     *
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on either VEVENT or VTODO.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in OldSabre\CalDAV\CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * @param mixed $calendarId
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery($calendarId, array $filters);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/NotificationSupport.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/NotificationSupport.php
new file mode 100644
index 0000000..a99170e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/NotificationSupport.php
@@ -0,0 +1,47 @@
+<?php
+
+namespace OldSabre\CalDAV\Backend;
+
+/**
+ * Adds caldav notification support to a backend.
+ *
+ * Note: This feature is experimental, and may change in between different
+ * SabreDAV versions.
+ *
+ * Notifications are defined at:
+ * http://svn.calendarserver.org/repository/calendarserver/CalendarServer/trunk/doc/Extensions/caldav-notifications.txt
+ *
+ * These notifications are basically a list of server-generated notifications
+ * displayed to the user. Users can dismiss notifications by deleting them.
+ *
+ * The primary usecase is to allow for calendar-sharing.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface NotificationSupport extends BackendInterface {
+
+    /**
+     * Returns a list of notifications for a given principal url.
+     *
+     * The returned array should only consist of implementations of
+     * \OldSabre\CalDAV\Notifications\INotificationType.
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getNotificationsForPrincipal($principalUri);
+
+    /**
+     * This deletes a specific notifcation.
+     *
+     * This may be called by a client once it deems a notification handled.
+     *
+     * @param string $principalUri
+     * @param \OldSabre\CalDAV\Notifications\INotificationType $notification
+     * @return void
+     */
+    public function deleteNotification($principalUri, \OldSabre\CalDAV\Notifications\INotificationType $notification);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/PDO.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/PDO.php
new file mode 100644
index 0000000..104deea
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/PDO.php
@@ -0,0 +1,691 @@
+<?php
+
+namespace OldSabre\CalDAV\Backend;
+
+use OldSabre\VObject;
+use OldSabre\CalDAV;
+use OldSabre\DAV;
+
+/**
+ * PDO CalDAV backend
+ *
+ * This backend is used to store calendar-data in a PDO database, such as
+ * sqlite or MySQL
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PDO extends AbstractBackend {
+
+    /**
+     * We need to specify a max date, because we need to stop *somewhere*
+     *
+     * On 32 bit system the maximum for a signed integer is 2147483647, so
+     * MAX_DATE cannot be higher than date('Y-m-d', 2147483647) which results
+     * in 2038-01-19 to avoid problems when the date is converted
+     * to a unix timestamp.
+     */
+    const MAX_DATE = '2038-01-01';
+
+    /**
+     * pdo
+     *
+     * @var \PDO
+     */
+    protected $pdo;
+
+    /**
+     * The table name that will be used for calendars
+     *
+     * @var string
+     */
+    protected $calendarTableName;
+
+    /**
+     * The table name that will be used for calendar objects
+     *
+     * @var string
+     */
+    protected $calendarObjectTableName;
+
+    /**
+     * List of CalDAV properties, and how they map to database fieldnames
+     * Add your own properties by simply adding on to this array.
+     *
+     * Note that only string-based properties are supported here.
+     *
+     * @var array
+     */
+    public $propertyMap = array(
+        '{DAV:}displayname'                          => 'displayname',
+        '{urn:ietf:params:xml:ns:caldav}calendar-description' => 'description',
+        '{urn:ietf:params:xml:ns:caldav}calendar-timezone'    => 'timezone',
+        '{http://apple.com/ns/ical/}calendar-order'  => 'calendarorder',
+        '{http://apple.com/ns/ical/}calendar-color'  => 'calendarcolor',
+    );
+
+    /**
+     * Creates the backend
+     *
+     * @param \PDO $pdo
+     * @param string $calendarTableName
+     * @param string $calendarObjectTableName
+     */
+    public function __construct(\PDO $pdo, $calendarTableName = 'calendars', $calendarObjectTableName = 'calendarobjects') {
+
+        $this->pdo = $pdo;
+        $this->calendarTableName = $calendarTableName;
+        $this->calendarObjectTableName = $calendarObjectTableName;
+
+    }
+
+    /**
+     * Returns a list of calendars for a principal.
+     *
+     * Every project is an array with the following keys:
+     *  * id, a unique id that will be used by other functions to modify the
+     *    calendar. This can be the same as the uri or a database key.
+     *  * uri, which the basename of the uri with which the calendar is
+     *    accessed.
+     *  * principaluri. The owner of the calendar. Almost always the same as
+     *    principalUri passed to this method.
+     *
+     * Furthermore it can contain webdav properties in clark notation. A very
+     * common one is '{DAV:}displayname'.
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getCalendarsForUser($principalUri) {
+
+        $fields = array_values($this->propertyMap);
+        $fields[] = 'id';
+        $fields[] = 'uri';
+        $fields[] = 'ctag';
+        $fields[] = 'components';
+        $fields[] = 'principaluri';
+        $fields[] = 'transparent';
+
+        // Making fields a comma-delimited list
+        $fields = implode(', ', $fields);
+        $stmt = $this->pdo->prepare("SELECT " . $fields . " FROM ".$this->calendarTableName." WHERE principaluri = ? ORDER BY calendarorder ASC");
+        $stmt->execute(array($principalUri));
+
+        $calendars = array();
+        while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+
+            $components = array();
+            if ($row['components']) {
+                $components = explode(',',$row['components']);
+            }
+
+            $calendar = array(
+                'id' => $row['id'],
+                'uri' => $row['uri'],
+                'principaluri' => $row['principaluri'],
+                '{' . CalDAV\Plugin::NS_CALENDARSERVER . '}getctag' => $row['ctag']?$row['ctag']:'0',
+                '{' . CalDAV\Plugin::NS_CALDAV . '}supported-calendar-component-set' => new CalDAV\Property\SupportedCalendarComponentSet($components),
+                '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-calendar-transp' => new CalDAV\Property\ScheduleCalendarTransp($row['transparent']?'transparent':'opaque'),
+            );
+
+
+            foreach($this->propertyMap as $xmlName=>$dbName) {
+                $calendar[$xmlName] = $row[$dbName];
+            }
+
+            $calendars[] = $calendar;
+
+        }
+
+        return $calendars;
+
+    }
+
+    /**
+     * Creates a new calendar for a principal.
+     *
+     * If the creation was a success, an id must be returned that can be used to reference
+     * this calendar in other methods, such as updateCalendar
+     *
+     * @param string $principalUri
+     * @param string $calendarUri
+     * @param array $properties
+     * @return string
+     */
+    public function createCalendar($principalUri, $calendarUri, array $properties) {
+
+        $fieldNames = array(
+            'principaluri',
+            'uri',
+            'ctag',
+            'transparent',
+        );
+        $values = array(
+            ':principaluri' => $principalUri,
+            ':uri'          => $calendarUri,
+            ':ctag'         => 1,
+            ':transparent'  => 0,
+        );
+
+        // Default value
+        $sccs = '{urn:ietf:params:xml:ns:caldav}supported-calendar-component-set';
+        $fieldNames[] = 'components';
+        if (!isset($properties[$sccs])) {
+            $values[':components'] = 'VEVENT,VTODO';
+        } else {
+            if (!($properties[$sccs] instanceof CalDAV\Property\SupportedCalendarComponentSet)) {
+                throw new DAV\Exception('The ' . $sccs . ' property must be of type: \OldSabre\CalDAV\Property\SupportedCalendarComponentSet');
+            }
+            $values[':components'] = implode(',',$properties[$sccs]->getValue());
+        }
+        $transp = '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-calendar-transp';
+        if (isset($properties[$transp])) {
+            $values[':transparent'] = $properties[$transp]->getValue()==='transparent';
+        }
+
+        foreach($this->propertyMap as $xmlName=>$dbName) {
+            if (isset($properties[$xmlName])) {
+
+                $values[':' . $dbName] = $properties[$xmlName];
+                $fieldNames[] = $dbName;
+            }
+        }
+
+        $stmt = $this->pdo->prepare("INSERT INTO ".$this->calendarTableName." (".implode(', ', $fieldNames).") VALUES (".implode(', ',array_keys($values)).")");
+        $stmt->execute($values);
+
+        return $this->pdo->lastInsertId();
+
+    }
+
+    /**
+     * Updates properties for a calendar.
+     *
+     * The mutations array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param string $calendarId
+     * @param array $mutations
+     * @return bool|array
+     */
+    public function updateCalendar($calendarId, array $mutations) {
+
+        $newValues = array();
+        $result = array(
+            200 => array(), // Ok
+            403 => array(), // Forbidden
+            424 => array(), // Failed Dependency
+        );
+
+        $hasError = false;
+
+        foreach($mutations as $propertyName=>$propertyValue) {
+
+            switch($propertyName) {
+                case '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-calendar-transp' :
+                    $fieldName = 'transparent';
+                    $newValues[$fieldName] = $propertyValue->getValue()==='transparent';
+                    break;
+                default :
+                    // Checking the property map
+                    if (!isset($this->propertyMap[$propertyName])) {
+                        // We don't know about this property.
+                        $hasError = true;
+                        $result[403][$propertyName] = null;
+                        unset($mutations[$propertyName]);
+                        continue;
+                    }
+
+                    $fieldName = $this->propertyMap[$propertyName];
+                    $newValues[$fieldName] = $propertyValue;
+            }
+
+        }
+
+        // If there were any errors we need to fail the request
+        if ($hasError) {
+            // Properties has the remaining properties
+            foreach($mutations as $propertyName=>$propertyValue) {
+                $result[424][$propertyName] = null;
+            }
+
+            // Removing unused statuscodes for cleanliness
+            foreach($result as $status=>$properties) {
+                if (is_array($properties) && count($properties)===0) unset($result[$status]);
+            }
+
+            return $result;
+
+        }
+
+        // Success
+
+        // Now we're generating the sql query.
+        $valuesSql = array();
+        foreach($newValues as $fieldName=>$value) {
+            $valuesSql[] = $fieldName . ' = ?';
+        }
+        $valuesSql[] = 'ctag = ctag + 1';
+
+        $stmt = $this->pdo->prepare("UPDATE " . $this->calendarTableName . " SET " . implode(', ',$valuesSql) . " WHERE id = ?");
+        $newValues['id'] = $calendarId;
+        $stmt->execute(array_values($newValues));
+
+        return true;
+
+    }
+
+    /**
+     * Delete a calendar and all it's objects
+     *
+     * @param string $calendarId
+     * @return void
+     */
+    public function deleteCalendar($calendarId) {
+
+        $stmt = $this->pdo->prepare('DELETE FROM '.$this->calendarObjectTableName.' WHERE calendarid = ?');
+        $stmt->execute(array($calendarId));
+
+        $stmt = $this->pdo->prepare('DELETE FROM '.$this->calendarTableName.' WHERE id = ?');
+        $stmt->execute(array($calendarId));
+
+    }
+
+    /**
+     * Returns all calendar objects within a calendar.
+     *
+     * Every item contains an array with the following keys:
+     *   * id - unique identifier which will be used for subsequent updates
+     *   * calendardata - The iCalendar-compatible calendar data
+     *   * uri - a unique key which will be used to construct the uri. This can be any arbitrary string.
+     *   * lastmodified - a timestamp of the last modification time
+     *   * etag - An arbitrary string, surrounded by double-quotes. (e.g.:
+     *   '  "abcdef"')
+     *   * calendarid - The calendarid as it was passed to this function.
+     *   * size - The size of the calendar objects, in bytes.
+     *
+     * Note that the etag is optional, but it's highly encouraged to return for
+     * speed reasons.
+     *
+     * The calendardata is also optional. If it's not returned
+     * 'getCalendarObject' will be called later, which *is* expected to return
+     * calendardata.
+     *
+     * If neither etag or size are specified, the calendardata will be
+     * used/fetched to determine these numbers. If both are specified the
+     * amount of times this is needed is reduced by a great degree.
+     *
+     * @param string $calendarId
+     * @return array
+     */
+    public function getCalendarObjects($calendarId) {
+
+        $stmt = $this->pdo->prepare('SELECT id, uri, lastmodified, etag, calendarid, size FROM '.$this->calendarObjectTableName.' WHERE calendarid = ?');
+        $stmt->execute(array($calendarId));
+
+        $result = array();
+        foreach($stmt->fetchAll(\PDO::FETCH_ASSOC) as $row) {
+            $result[] = array(
+                'id'           => $row['id'],
+                'uri'          => $row['uri'],
+                'lastmodified' => $row['lastmodified'],
+                'etag'         => '"' . $row['etag'] . '"',
+                'calendarid'   => $row['calendarid'],
+                'size'         => (int)$row['size'],
+            );
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Returns information from a single calendar object, based on it's object
+     * uri.
+     *
+     * The returned array must have the same keys as getCalendarObjects. The
+     * 'calendardata' object is required here though, while it's not required
+     * for getCalendarObjects.
+     *
+     * This method must return null if the object did not exist.
+     *
+     * @param string $calendarId
+     * @param string $objectUri
+     * @return array|null
+     */
+    public function getCalendarObject($calendarId,$objectUri) {
+
+        $stmt = $this->pdo->prepare('SELECT id, uri, lastmodified, etag, calendarid, size, calendardata FROM '.$this->calendarObjectTableName.' WHERE calendarid = ? AND uri = ?');
+        $stmt->execute(array($calendarId, $objectUri));
+        $row = $stmt->fetch(\PDO::FETCH_ASSOC);
+
+        if(!$row) return null;
+
+        return array(
+            'id'           => $row['id'],
+            'uri'          => $row['uri'],
+            'lastmodified' => $row['lastmodified'],
+            'etag'         => '"' . $row['etag'] . '"',
+            'calendarid'   => $row['calendarid'],
+            'size'         => (int)$row['size'],
+            'calendardata' => $row['calendardata'],
+         );
+
+    }
+
+
+    /**
+     * Creates a new calendar object.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function createCalendarObject($calendarId,$objectUri,$calendarData) {
+
+        $extraData = $this->getDenormalizedData($calendarData);
+
+        $stmt = $this->pdo->prepare('INSERT INTO '.$this->calendarObjectTableName.' (calendarid, uri, calendardata, lastmodified, etag, size, componenttype, firstoccurence, lastoccurence) VALUES (?,?,?,?,?,?,?,?,?)');
+        $stmt->execute(array(
+            $calendarId,
+            $objectUri,
+            $calendarData,
+            time(),
+            $extraData['etag'],
+            $extraData['size'],
+            $extraData['componentType'],
+            $extraData['firstOccurence'],
+            $extraData['lastOccurence'],
+        ));
+        $stmt = $this->pdo->prepare('UPDATE '.$this->calendarTableName.' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt->execute(array($calendarId));
+
+        return '"' . $extraData['etag'] . '"';
+
+    }
+
+    /**
+     * Updates an existing calendarobject, based on it's uri.
+     *
+     * It is possible return an etag from this function, which will be used in
+     * the response to this PUT request. Note that the ETag must be surrounded
+     * by double-quotes.
+     *
+     * However, you should only really return this ETag if you don't mangle the
+     * calendar-data. If the result of a subsequent GET to this object is not
+     * the exact same as this request body, you should omit the ETag.
+     *
+     * @param mixed $calendarId
+     * @param string $objectUri
+     * @param string $calendarData
+     * @return string|null
+     */
+    public function updateCalendarObject($calendarId,$objectUri,$calendarData) {
+
+        $extraData = $this->getDenormalizedData($calendarData);
+
+        $stmt = $this->pdo->prepare('UPDATE '.$this->calendarObjectTableName.' SET calendardata = ?, lastmodified = ?, etag = ?, size = ?, componenttype = ?, firstoccurence = ?, lastoccurence = ? WHERE calendarid = ? AND uri = ?');
+        $stmt->execute(array($calendarData,time(), $extraData['etag'], $extraData['size'], $extraData['componentType'], $extraData['firstOccurence'], $extraData['lastOccurence'] ,$calendarId,$objectUri));
+        $stmt = $this->pdo->prepare('UPDATE '.$this->calendarTableName.' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt->execute(array($calendarId));
+
+        return '"' . $extraData['etag'] . '"';
+
+    }
+
+    /**
+     * Parses some information from calendar objects, used for optimized
+     * calendar-queries.
+     *
+     * Returns an array with the following keys:
+     *   * etag
+     *   * size
+     *   * componentType
+     *   * firstOccurence
+     *   * lastOccurence
+     *
+     * @param string $calendarData
+     * @return array
+     */
+    protected function getDenormalizedData($calendarData) {
+
+        $vObject = VObject\Reader::read($calendarData);
+        $componentType = null;
+        $component = null;
+        $firstOccurence = null;
+        $lastOccurence = null;
+        foreach($vObject->getComponents() as $component) {
+            if ($component->name!=='VTIMEZONE') {
+                $componentType = $component->name;
+                break;
+            }
+        }
+        if (!$componentType) {
+            throw new \OldSabre\DAV\Exception\BadRequest('Calendar objects must have a VJOURNAL, VEVENT or VTODO component');
+        }
+        if ($componentType === 'VEVENT') {
+            $firstOccurence = $component->DTSTART->getDateTime()->getTimeStamp();
+            // Finding the last occurence is a bit harder
+            if (!isset($component->RRULE)) {
+                if (isset($component->DTEND)) {
+                    $lastOccurence = $component->DTEND->getDateTime()->getTimeStamp();
+                } elseif (isset($component->DURATION)) {
+                    $endDate = clone $component->DTSTART->getDateTime();
+                    $endDate->add(VObject\DateTimeParser::parse($component->DURATION->getValue()));
+                    $lastOccurence = $endDate->getTimeStamp();
+                } elseif (!$component->DTSTART->hasTime()) {
+                    $endDate = clone $component->DTSTART->getDateTime();
+                    $endDate->modify('+1 day');
+                    $lastOccurence = $endDate->getTimeStamp();
+                } else {
+                    $lastOccurence = $firstOccurence;
+                }
+            } else {
+                $it = new VObject\RecurrenceIterator($vObject, (string)$component->UID);
+                $maxDate = new \DateTime(self::MAX_DATE);
+                if ($it->isInfinite()) {
+                    $lastOccurence = $maxDate->getTimeStamp();
+                } else {
+                    $end = $it->getDtEnd();
+                    while($it->valid() && $end < $maxDate) {
+                        $end = $it->getDtEnd();
+                        $it->next();
+
+                    }
+                    $lastOccurence = $end->getTimeStamp();
+                }
+
+            }
+        }
+
+        return array(
+            'etag' => md5($calendarData),
+            'size' => strlen($calendarData),
+            'componentType' => $componentType,
+            'firstOccurence' => $firstOccurence,
+            'lastOccurence'  => $lastOccurence,
+        );
+
+    }
+
+    /**
+     * Deletes an existing calendar object.
+     *
+     * @param string $calendarId
+     * @param string $objectUri
+     * @return void
+     */
+    public function deleteCalendarObject($calendarId,$objectUri) {
+
+        $stmt = $this->pdo->prepare('DELETE FROM '.$this->calendarObjectTableName.' WHERE calendarid = ? AND uri = ?');
+        $stmt->execute(array($calendarId,$objectUri));
+        $stmt = $this->pdo->prepare('UPDATE '. $this->calendarTableName .' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt->execute(array($calendarId));
+
+    }
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by \OldSabre\CalDAV\CalendarQueryParser.
+     *
+     * Note that it is extremely likely that getCalendarObject for every path
+     * returned from this method will be called almost immediately after. You
+     * may want to anticipate this to speed up these requests.
+     *
+     * This method provides a default implementation, which parses *all* the
+     * iCalendar objects in the specified calendar.
+     *
+     * This default may well be good enough for personal use, and calendars
+     * that aren't very large. But if you anticipate high usage, big calendars
+     * or high loads, you are strongly adviced to optimize certain paths.
+     *
+     * The best way to do so is override this method and to optimize
+     * specifically for 'common filters'.
+     *
+     * Requests that are extremely common are:
+     *   * requests for just VEVENTS
+     *   * requests for just VTODO
+     *   * requests with a time-range-filter on a VEVENT.
+     *
+     * ..and combinations of these requests. It may not be worth it to try to
+     * handle every possible situation and just rely on the (relatively
+     * easy to use) CalendarQueryValidator to handle the rest.
+     *
+     * Note that especially time-range-filters may be difficult to parse. A
+     * time-range filter specified on a VEVENT must for instance also handle
+     * recurrence rules correctly.
+     * A good example of how to interprete all these filters can also simply
+     * be found in \OldSabre\CalDAV\CalendarQueryFilter. This class is as correct
+     * as possible, so it gives you a good idea on what type of stuff you need
+     * to think of.
+     *
+     * This specific implementation (for the PDO) backend optimizes filters on
+     * specific components, and VEVENT time-ranges.
+     *
+     * @param string $calendarId
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery($calendarId, array $filters) {
+
+        $result = array();
+        $validator = new \OldSabre\CalDAV\CalendarQueryValidator();
+
+        $componentType = null;
+        $requirePostFilter = true;
+        $timeRange = null;
+
+        // if no filters were specified, we don't need to filter after a query
+        if (!$filters['prop-filters'] && !$filters['comp-filters']) {
+            $requirePostFilter = false;
+        }
+
+        // Figuring out if there's a component filter
+        if (count($filters['comp-filters']) > 0 && !$filters['comp-filters'][0]['is-not-defined']) {
+            $componentType = $filters['comp-filters'][0]['name'];
+
+            // Checking if we need post-filters
+            if (!$filters['prop-filters'] && !$filters['comp-filters'][0]['comp-filters'] && !$filters['comp-filters'][0]['time-range'] && !$filters['comp-filters'][0]['prop-filters']) {
+                $requirePostFilter = false;
+            }
+            // There was a time-range filter
+            if ($componentType == 'VEVENT' && isset($filters['comp-filters'][0]['time-range'])) {
+                $timeRange = $filters['comp-filters'][0]['time-range'];
+
+                // If start time OR the end time is not specified, we can do a
+                // 100% accurate mysql query.
+                if (!$filters['prop-filters'] && !$filters['comp-filters'][0]['comp-filters'] && !$filters['comp-filters'][0]['prop-filters'] && (!$timeRange['start'] || !$timeRange['end'])) {
+                    $requirePostFilter = false;
+                }
+            }
+
+        }
+
+        if ($requirePostFilter) {
+            $query = "SELECT uri, calendardata FROM ".$this->calendarObjectTableName." WHERE calendarid = :calendarid";
+        } else {
+            $query = "SELECT uri FROM ".$this->calendarObjectTableName." WHERE calendarid = :calendarid";
+        }
+
+        $values = array(
+            'calendarid' => $calendarId,
+        );
+
+        if ($componentType) {
+            $query.=" AND componenttype = :componenttype";
+            $values['componenttype'] = $componentType;
+        }
+
+        if ($timeRange && $timeRange['start']) {
+            $query.=" AND lastoccurence > :startdate";
+            $values['startdate'] = $timeRange['start']->getTimeStamp();
+        }
+        if ($timeRange && $timeRange['end']) {
+            $query.=" AND firstoccurence < :enddate";
+            $values['enddate'] = $timeRange['end']->getTimeStamp();
+        }
+
+        $stmt = $this->pdo->prepare($query);
+        $stmt->execute($values);
+
+        $result = array();
+        while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+            if ($requirePostFilter) {
+                if (!$this->validateFilterForObject($row, $filters)) {
+                    continue;
+                }
+            }
+            $result[] = $row['uri'];
+
+        }
+
+        return $result;
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/SharingSupport.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/SharingSupport.php
new file mode 100644
index 0000000..626eade
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Backend/SharingSupport.php
@@ -0,0 +1,243 @@
+<?php
+
+namespace OldSabre\CalDAV\Backend;
+
+/**
+ * Adds support for sharing features to a CalDAV server.
+ *
+ * Note: This feature is experimental, and may change in between different
+ * SabreDAV versions.
+ *
+ * Early warning: Currently SabreDAV provides no implementation for this. This
+ * is, because in it's current state there is no elegant way to do this.
+ * The problem lies in the fact that a real CalDAV server with sharing support
+ * would first need email support (with invite notifications), and really also
+ * a browser-frontend that allows people to accept or reject these shares.
+ *
+ * In addition, the CalDAV backends are currently kept as independent as
+ * possible, and should not be aware of principals, email addresses or
+ * accounts.
+ *
+ * Adding an implementation for Sharing to standard-sabredav would contradict
+ * these goals, so for this reason this is currently not implemented, although
+ * it may very well in the future; but probably not before SabreDAV 2.0.
+ *
+ * The interface works however, so if you implement all this, and do it
+ * correctly sharing _will_ work. It's not particularly easy, and I _urge you_
+ * to make yourself acquainted with the following document first:
+ *
+ * https://trac.calendarserver.org/browser/CalendarServer/trunk/doc/Extensions/caldav-sharing.txt
+ *
+ * An overview
+ * ===========
+ *
+ * Implementing this interface will allow a user to share his or her calendars
+ * to other users. Effectively, when a calendar is shared the calendar will
+ * show up in both the Sharer's and Sharee's calendar-home root.
+ * This interface adds a few methods that ensure that this happens, and there
+ * are also a number of new requirements in the base-class you must now follow.
+ *
+ *
+ * How it works
+ * ============
+ *
+ * When a user shares a calendar, the updateShares() method will be called with
+ * a list of sharees that are now added, and a list of sharees that have been
+ * removed.
+ * Removal is instant, but when a sharee is added the sharee first gets a
+ * chance to accept or reject the invitation for a share.
+ *
+ * After a share is accepted, the calendar will be returned from
+ * getUserCalendars for both the sharer, and the sharee.
+ *
+ * If the sharee deletes the calendar, only their share gets deleted. When the
+ * owner deletes a calendar, it will be removed for everybody.
+ *
+ *
+ * Notifications
+ * =============
+ *
+ * During all these sharing operations, a lot of notifications are sent back
+ * and forward.
+ *
+ * Whenever the list of sharees for a calendar has been changed (they have been
+ * added, removed or modified) all sharees should get a notification for this
+ * change.
+ * This notification is always represented by:
+ *
+ * OldSabre\CalDAV\Notifications\Notification\Invite
+ *
+ * In the case of an invite, the sharee may reply with an 'accept' or
+ * 'decline'. These are always represented by:
+ *
+ * OldSabre\CalDAV\Notifications\Notification\Invite
+ *
+ *
+ * Calendar access by sharees
+ * ==========================
+ *
+ * As mentioned earlier, shared calendars must now also be returned for
+ * getCalendarsForUser for sharees. A few things change though.
+ *
+ * The following properties must be specified:
+ *
+ * 1. {http://calendarserver.org/ns/}shared-url
+ *
+ * This property MUST contain the url to the original calendar, that is.. the
+ * path to the calendar from the owner.
+ *
+ * 2. {http://sabredav.org/ns}owner-principal
+ *
+ * This is a url to to the principal who is sharing the calendar.
+ *
+ * 3. {http://sabredav.org/ns}read-only
+ *
+ * This should be either 0 or 1, depending on if the user has read-only or
+ * read-write access to the calendar.
+ *
+ * Only when this is done, the calendar will correctly be marked as a calendar
+ * that's shared to him, thus allowing clients to display the correct interface
+ * and ACL enforcement.
+ *
+ * If a sharee deletes their calendar, only their instance of the calendar
+ * should be deleted, the original should still exists.
+ * Pretty much any 'dead' WebDAV properties on these shared calendars should be
+ * specific to a user. This means that if the displayname is changed by a
+ * sharee, the original is not affected. This is also true for:
+ *   * The description
+ *   * The color
+ *   * The order
+ *   * And any other dead properties.
+ *
+ * Properties like a ctag should not be different for multiple instances of the
+ * calendar.
+ *
+ * Lastly, objects *within* calendars should also have user-specific data. The
+ * two things that are user-specific are:
+ *   * VALARM objects
+ *   * The TRANSP property
+ *
+ * This _also_ implies that if a VALARM is deleted by a sharee for some event,
+ * this has no effect on the original VALARM.
+ *
+ * Understandably, the this last requirement is one of the hardest.
+ * Realisticly, I can see people ignoring this part of the spec, but that could
+ * cause a different set of issues.
+ *
+ *
+ * Publishing
+ * ==========
+ *
+ * When a user publishes a url, the server should generate a 'publish url'.
+ * This is a read-only url, anybody can use to consume the calendar feed.
+ *
+ * Calendars are in one of two states:
+ *   * published
+ *   * unpublished
+ *
+ * If a calendar is published, the following property should be returned
+ * for each calendar in getCalendarsForPrincipal.
+ *
+ * {http://calendarserver.org/ns/}publish-url
+ *
+ * This element should contain a {DAV:}href element, which points to the
+ * public url that does not require authentication. Unlike every other href,
+ * this url must be absolute.
+ *
+ * Ideally, the following property is always returned
+ *
+ * {http://calendarserver.org/ns/}pre-publish-url
+ *
+ * This property should contain the url that the calendar _would_ have, if it
+ * were to be published. iCal uses this to display the url, before the user
+ * will actually publish it.
+ *
+ *
+ * Selectively disabling publish or share feature
+ * ==============================================
+ *
+ * If OldSabre\CalDAV\Property\AllowedSharingModes is returned from
+ * getCalendarsByUser, this allows the server to specify whether either sharing,
+ * or publishing is supported.
+ *
+ * This allows a client to determine in advance which features are available,
+ * and update the interface appropriately. If this property is not returned by
+ * the backend, the SharingPlugin automatically injects it and assumes both
+ * features are available.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface SharingSupport extends NotificationSupport {
+
+    /**
+     * Updates the list of shares.
+     *
+     * The first array is a list of people that are to be added to the
+     * calendar.
+     *
+     * Every element in the add array has the following properties:
+     *   * href - A url. Usually a mailto: address
+     *   * commonName - Usually a first and last name, or false
+     *   * summary - A description of the share, can also be false
+     *   * readOnly - A boolean value
+     *
+     * Every element in the remove array is just the address string.
+     *
+     * Note that if the calendar is currently marked as 'not shared' by and
+     * this method is called, the calendar should be 'upgraded' to a shared
+     * calendar.
+     *
+     * @param mixed $calendarId
+     * @param array $add
+     * @param array $remove
+     * @return void
+     */
+    function updateShares($calendarId, array $add, array $remove);
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the OldSabre\CalDAV\SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * This method may be called by either the original instance of the
+     * calendar, as well as the shared instances. In the case of the shared
+     * instances, it is perfectly acceptable to return an empty array in case
+     * there are privacy concerns.
+     *
+     * @param mixed $calendarId
+     * @return array
+     */
+    function getShares($calendarId);
+
+    /**
+     * This method is called when a user replied to a request to share.
+     *
+     * If the user chose to accept the share, this method should return the
+     * newly created calendar url.
+     *
+     * @param string href The sharee who is replying (often a mailto: address)
+     * @param int status One of the SharingPlugin::STATUS_* constants
+     * @param string $calendarUri The url to the calendar thats being shared
+     * @param string $inReplyTo The unique id this message is a response to
+     * @param string $summary A description of the reply
+     * @return null|string
+     */
+    function shareReply($href, $status, $calendarUri, $inReplyTo, $summary = null);
+
+    /**
+     * Publishes a calendar
+     *
+     * @param mixed $calendarId
+     * @param bool $value
+     * @return void
+     */
+    function setPublishStatus($calendarId, $value);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Calendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Calendar.php
new file mode 100644
index 0000000..bfd4990
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Calendar.php
@@ -0,0 +1,376 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * This object represents a CalDAV calendar.
+ *
+ * A calendar can contain multiple TODO and or Events. These are represented
+ * as \OldSabre\CalDAV\CalendarObject objects.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Calendar implements ICalendar, DAV\IProperties, DAVACL\IACL {
+
+    /**
+     * This is an array with calendar information
+     *
+     * @var array
+     */
+    protected $calendarInfo;
+
+    /**
+     * CalDAV backend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $caldavBackend;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $caldavBackend
+     * @param array $calendarInfo
+     */
+    public function __construct(Backend\BackendInterface $caldavBackend, $calendarInfo) {
+
+        $this->caldavBackend = $caldavBackend;
+        $this->calendarInfo = $calendarInfo;
+
+    }
+
+    /**
+     * Returns the name of the calendar
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->calendarInfo['uri'];
+
+    }
+
+    /**
+     * Updates properties such as the display name and description
+     *
+     * @param array $mutations
+     * @return array
+     */
+    public function updateProperties($mutations) {
+
+        return $this->caldavBackend->updateCalendar($this->calendarInfo['id'],$mutations);
+
+    }
+
+    /**
+     * Returns the list of properties
+     *
+     * @param array $requestedProperties
+     * @return array
+     */
+    public function getProperties($requestedProperties) {
+
+        $response = array();
+
+        foreach($requestedProperties as $prop) switch($prop) {
+
+            case '{urn:ietf:params:xml:ns:caldav}supported-calendar-data' :
+                $response[$prop] = new Property\SupportedCalendarData();
+                break;
+            case '{urn:ietf:params:xml:ns:caldav}supported-collation-set' :
+                $response[$prop] =  new Property\SupportedCollationSet();
+                break;
+            case '{DAV:}owner' :
+                $response[$prop] = new DAVACL\Property\Principal(DAVACL\Property\Principal::HREF,$this->calendarInfo['principaluri']);
+                break;
+            default :
+                if (isset($this->calendarInfo[$prop])) $response[$prop] = $this->calendarInfo[$prop];
+                break;
+
+        }
+        return $response;
+
+    }
+
+    /**
+     * Returns a calendar object
+     *
+     * The contained calendar objects are for example Events or Todo's.
+     *
+     * @param string $name
+     * @return \OldSabre\CalDAV\ICalendarObject
+     */
+    public function getChild($name) {
+
+        $obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'],$name);
+
+        if (!$obj) throw new DAV\Exception\NotFound('Calendar object not found');
+
+        $obj['acl'] = $this->getACL();
+        // Removing the irrelivant
+        foreach($obj['acl'] as $key=>$acl) {
+            if ($acl['privilege'] === '{' . Plugin::NS_CALDAV . '}read-free-busy') {
+                unset($obj['acl'][$key]);
+            }
+        }
+
+        return new CalendarObject($this->caldavBackend,$this->calendarInfo,$obj);
+
+    }
+
+    /**
+     * Returns the full list of calendar objects
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        $objs = $this->caldavBackend->getCalendarObjects($this->calendarInfo['id']);
+        $children = array();
+        foreach($objs as $obj) {
+            $obj['acl'] = $this->getACL();
+            // Removing the irrelivant
+            foreach($obj['acl'] as $key=>$acl) {
+                if ($acl['privilege'] === '{' . Plugin::NS_CALDAV . '}read-free-busy') {
+                    unset($obj['acl'][$key]);
+                }
+            }
+            $children[] = new CalendarObject($this->caldavBackend,$this->calendarInfo,$obj);
+        }
+        return $children;
+
+    }
+
+    /**
+     * Checks if a child-node exists.
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function childExists($name) {
+
+        $obj = $this->caldavBackend->getCalendarObject($this->calendarInfo['id'],$name);
+        if (!$obj)
+            return false;
+        else
+            return true;
+
+    }
+
+    /**
+     * Creates a new directory
+     *
+     * We actually block this, as subdirectories are not allowed in calendars.
+     *
+     * @param string $name
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating collections in calendar objects is not allowed');
+
+    }
+
+    /**
+     * Creates a new file
+     *
+     * The contents of the new file must be a valid ICalendar string.
+     *
+     * @param string $name
+     * @param resource $calendarData
+     * @return string|null
+     */
+    public function createFile($name,$calendarData = null) {
+
+        if (is_resource($calendarData)) {
+            $calendarData = stream_get_contents($calendarData);
+        }
+        return $this->caldavBackend->createCalendarObject($this->calendarInfo['id'],$name,$calendarData);
+
+    }
+
+    /**
+     * Deletes the calendar.
+     *
+     * @return void
+     */
+    public function delete() {
+
+        $this->caldavBackend->deleteCalendar($this->calendarInfo['id']);
+
+    }
+
+    /**
+     * Renames the calendar. Note that most calendars use the
+     * {DAV:}displayname to display a name to display a name.
+     *
+     * @param string $newName
+     * @return void
+     */
+    public function setName($newName) {
+
+        throw new DAV\Exception\MethodNotAllowed('Renaming calendars is not yet supported');
+
+    }
+
+    /**
+     * Returns the last modification date as a unix timestamp.
+     *
+     * @return void
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->calendarInfo['principaluri'];
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->getOwner(),
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->getOwner(),
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->getOwner() . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->getOwner() . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->getOwner() . '/calendar-proxy-read',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{' . Plugin::NS_CALDAV . '}read-free-busy',
+                'principal' => '{DAV:}authenticated',
+                'protected' => true,
+            ),
+
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See \OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        $default = DAVACL\Plugin::getDefaultSupportedPrivilegeSet();
+
+        // We need to inject 'read-free-busy' in the tree, aggregated under
+        // {DAV:}read.
+        foreach($default['aggregates'] as &$agg) {
+
+            if ($agg['privilege'] !== '{DAV:}read') continue;
+
+            $agg['aggregates'][] = array(
+                'privilege' => '{' . Plugin::NS_CALDAV . '}read-free-busy',
+            );
+
+        }
+        return $default;
+
+    }
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by OldSabre\CalDAV\CalendarQueryParser.
+     *
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery(array $filters) {
+
+        return $this->caldavBackend->calendarQuery($this->calendarInfo['id'], $filters);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarObject.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarObject.php
new file mode 100644
index 0000000..a60da8f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarObject.php
@@ -0,0 +1,279 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+/**
+ * The CalendarObject represents a single VEVENT or VTODO within a Calendar.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class CalendarObject extends \OldSabre\DAV\File implements ICalendarObject, \OldSabre\DAVACL\IACL {
+
+    /**
+     * OldSabre\CalDAV\Backend\BackendInterface
+     *
+     * @var OldSabre\CalDAV\Backend\AbstractBackend
+     */
+    protected $caldavBackend;
+
+    /**
+     * Array with information about this CalendarObject
+     *
+     * @var array
+     */
+    protected $objectData;
+
+    /**
+     * Array with information about the containing calendar
+     *
+     * @var array
+     */
+    protected $calendarInfo;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $caldavBackend
+     * @param array $calendarInfo
+     * @param array $objectData
+     */
+    public function __construct(Backend\BackendInterface $caldavBackend,array $calendarInfo,array $objectData) {
+
+        $this->caldavBackend = $caldavBackend;
+
+        if (!isset($objectData['calendarid'])) {
+            throw new \InvalidArgumentException('The objectData argument must contain a \'calendarid\' property');
+        }
+        if (!isset($objectData['uri'])) {
+            throw new \InvalidArgumentException('The objectData argument must contain an \'uri\' property');
+        }
+
+        $this->calendarInfo = $calendarInfo;
+        $this->objectData = $objectData;
+
+    }
+
+    /**
+     * Returns the uri for this object
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->objectData['uri'];
+
+    }
+
+    /**
+     * Returns the ICalendar-formatted object
+     *
+     * @return string
+     */
+    public function get() {
+
+        // Pre-populating the 'calendardata' is optional, if we don't have it
+        // already we fetch it from the backend.
+        if (!isset($this->objectData['calendardata'])) {
+            $this->objectData = $this->caldavBackend->getCalendarObject($this->objectData['calendarid'], $this->objectData['uri']);
+        }
+        return $this->objectData['calendardata'];
+
+    }
+
+    /**
+     * Updates the ICalendar-formatted object
+     *
+     * @param string|resource $calendarData
+     * @return string
+     */
+    public function put($calendarData) {
+
+        if (is_resource($calendarData)) {
+            $calendarData = stream_get_contents($calendarData);
+        }
+        $etag = $this->caldavBackend->updateCalendarObject($this->calendarInfo['id'],$this->objectData['uri'],$calendarData);
+        $this->objectData['calendardata'] = $calendarData;
+        $this->objectData['etag'] = $etag;
+
+        return $etag;
+
+    }
+
+    /**
+     * Deletes the calendar object
+     *
+     * @return void
+     */
+    public function delete() {
+
+        $this->caldavBackend->deleteCalendarObject($this->calendarInfo['id'],$this->objectData['uri']);
+
+    }
+
+    /**
+     * Returns the mime content-type
+     *
+     * @return string
+     */
+    public function getContentType() {
+
+        return 'text/calendar; charset=utf-8';
+
+    }
+
+    /**
+     * Returns an ETag for this object.
+     *
+     * The ETag is an arbitrary string, but MUST be surrounded by double-quotes.
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        if (isset($this->objectData['etag'])) {
+            return $this->objectData['etag'];
+        } else {
+            return '"' . md5($this->get()). '"';
+        }
+
+    }
+
+    /**
+     * Returns the last modification date as a unix timestamp
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return $this->objectData['lastmodified'];
+
+    }
+
+    /**
+     * Returns the size of this object in bytes
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        if (array_key_exists('size',$this->objectData)) {
+            return $this->objectData['size'];
+        } else {
+            return strlen($this->get());
+        }
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->calendarInfo['principaluri'];
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        // An alternative acl may be specified in the object data.
+        if (isset($this->objectData['acl'])) {
+            return $this->objectData['acl'];
+        }
+
+        // The default ACL
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->calendarInfo['principaluri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->calendarInfo['principaluri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->calendarInfo['principaluri'] . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->calendarInfo['principaluri'] . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->calendarInfo['principaluri'] . '/calendar-proxy-read',
+                'protected' => true,
+            ),
+
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new \OldSabre\DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See \OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryParser.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryParser.php
new file mode 100644
index 0000000..a2a2b75
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryParser.php
@@ -0,0 +1,298 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\VObject;
+
+/**
+ * Parses the calendar-query report request body.
+ *
+ * Whoever designed this format, and the CalDAV equivalent even more so,
+ * has no feel for design.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class CalendarQueryParser {
+
+    /**
+     * List of requested properties the client wanted
+     *
+     * @var array
+     */
+    public $requestedProperties;
+
+    /**
+     * List of property/component filters.
+     *
+     * @var array
+     */
+    public $filters;
+
+    /**
+     * This property will contain null if CALDAV:expand was not specified,
+     * otherwise it will contain an array with 2 elements (start, end). Each
+     * contain a DateTime object.
+     *
+     * If expand is specified, recurring calendar objects are to be expanded
+     * into their individual components, and only the components that fall
+     * within the specified time-range are to be returned.
+     *
+     * For more details, see rfc4791, section 9.6.5.
+     *
+     * @var null|array
+     */
+    public $expand;
+
+    /**
+     * DOM Document
+     *
+     * @var DOMDocument
+     */
+    protected $dom;
+
+    /**
+     * DOM XPath object
+     *
+     * @var DOMXPath
+     */
+    protected $xpath;
+
+    /**
+     * Creates the parser
+     *
+     * @param \DOMDocument $dom
+     */
+    public function __construct(\DOMDocument $dom) {
+
+        $this->dom = $dom;
+        $this->xpath = new \DOMXPath($dom);
+        $this->xpath->registerNameSpace('cal',Plugin::NS_CALDAV);
+        $this->xpath->registerNameSpace('dav','urn:DAV');
+
+    }
+
+    /**
+     * Parses the request.
+     *
+     * @return void
+     */
+    public function parse() {
+
+        $filterNode = null;
+
+        $filter = $this->xpath->query('/cal:calendar-query/cal:filter');
+        if ($filter->length !== 1) {
+            throw new \OldSabre\DAV\Exception\BadRequest('Only one filter element is allowed');
+        }
+
+        $compFilters = $this->parseCompFilters($filter->item(0));
+        if (count($compFilters)!==1) {
+            throw new \OldSabre\DAV\Exception\BadRequest('There must be exactly 1 top-level comp-filter.');
+        }
+
+        $this->filters = $compFilters[0];
+        $this->requestedProperties = array_keys(\OldSabre\DAV\XMLUtil::parseProperties($this->dom->firstChild));
+
+        $expand = $this->xpath->query('/cal:calendar-query/dav:prop/cal:calendar-data/cal:expand');
+        if ($expand->length>0) {
+            $this->expand = $this->parseExpand($expand->item(0));
+        }
+
+
+    }
+
+    /**
+     * Parses all the 'comp-filter' elements from a node
+     *
+     * @param \DOMElement $parentNode
+     * @return array
+     */
+    protected function parseCompFilters(\DOMElement $parentNode) {
+
+        $compFilterNodes = $this->xpath->query('cal:comp-filter', $parentNode);
+        $result = array();
+
+        for($ii=0; $ii < $compFilterNodes->length; $ii++) {
+
+            $compFilterNode = $compFilterNodes->item($ii);
+
+            $compFilter = array();
+            $compFilter['name'] = $compFilterNode->getAttribute('name');
+            $compFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $compFilterNode)->length>0;
+            $compFilter['comp-filters'] = $this->parseCompFilters($compFilterNode);
+            $compFilter['prop-filters'] = $this->parsePropFilters($compFilterNode);
+            $compFilter['time-range'] = $this->parseTimeRange($compFilterNode);
+
+            if ($compFilter['time-range'] && !in_array($compFilter['name'],array(
+                'VEVENT',
+                'VTODO',
+                'VJOURNAL',
+                'VFREEBUSY',
+                'VALARM',
+            ))) {
+                throw new \OldSabre\DAV\Exception\BadRequest('The time-range filter is not defined for the ' . $compFilter['name'] . ' component');
+            };
+
+            $result[] = $compFilter;
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Parses all the prop-filter elements from a node
+     *
+     * @param \DOMElement $parentNode
+     * @return array
+     */
+    protected function parsePropFilters(\DOMElement $parentNode) {
+
+        $propFilterNodes = $this->xpath->query('cal:prop-filter', $parentNode);
+        $result = array();
+
+        for ($ii=0; $ii < $propFilterNodes->length; $ii++) {
+
+            $propFilterNode = $propFilterNodes->item($ii);
+            $propFilter = array();
+            $propFilter['name'] = $propFilterNode->getAttribute('name');
+            $propFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $propFilterNode)->length>0;
+            $propFilter['param-filters'] = $this->parseParamFilters($propFilterNode);
+            $propFilter['text-match'] = $this->parseTextMatch($propFilterNode);
+            $propFilter['time-range'] = $this->parseTimeRange($propFilterNode);
+
+            $result[] = $propFilter;
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Parses the param-filter element
+     *
+     * @param \DOMElement $parentNode
+     * @return array
+     */
+    protected function parseParamFilters(\DOMElement $parentNode) {
+
+        $paramFilterNodes = $this->xpath->query('cal:param-filter', $parentNode);
+        $result = array();
+
+        for($ii=0;$ii<$paramFilterNodes->length;$ii++) {
+
+            $paramFilterNode = $paramFilterNodes->item($ii);
+            $paramFilter = array();
+            $paramFilter['name'] = $paramFilterNode->getAttribute('name');
+            $paramFilter['is-not-defined'] = $this->xpath->query('cal:is-not-defined', $paramFilterNode)->length>0;
+            $paramFilter['text-match'] = $this->parseTextMatch($paramFilterNode);
+
+            $result[] = $paramFilter;
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Parses the text-match element
+     *
+     * @param \DOMElement $parentNode
+     * @return array|null
+     */
+    protected function parseTextMatch(\DOMElement $parentNode) {
+
+        $textMatchNodes = $this->xpath->query('cal:text-match', $parentNode);
+
+        if ($textMatchNodes->length === 0)
+            return null;
+
+        $textMatchNode = $textMatchNodes->item(0);
+        $negateCondition = $textMatchNode->getAttribute('negate-condition');
+        $negateCondition = $negateCondition==='yes';
+        $collation = $textMatchNode->getAttribute('collation');
+        if (!$collation) $collation = 'i;ascii-casemap';
+
+        return array(
+            'negate-condition' => $negateCondition,
+            'collation' => $collation,
+            'value' => $textMatchNode->nodeValue
+        );
+
+    }
+
+    /**
+     * Parses the time-range element
+     *
+     * @param \DOMElement $parentNode
+     * @return array|null
+     */
+    protected function parseTimeRange(\DOMElement $parentNode) {
+
+        $timeRangeNodes = $this->xpath->query('cal:time-range', $parentNode);
+        if ($timeRangeNodes->length === 0) {
+            return null;
+        }
+
+        $timeRangeNode = $timeRangeNodes->item(0);
+
+        if ($start = $timeRangeNode->getAttribute('start')) {
+            $start = VObject\DateTimeParser::parseDateTime($start);
+        } else {
+            $start = null;
+        }
+        if ($end = $timeRangeNode->getAttribute('end')) {
+            $end = VObject\DateTimeParser::parseDateTime($end);
+        } else {
+            $end = null;
+        }
+
+        if (!is_null($start) && !is_null($end) && $end <= $start) {
+            throw new \OldSabre\DAV\Exception\BadRequest('The end-date must be larger than the start-date in the time-range filter');
+        }
+
+        return array(
+            'start' => $start,
+            'end' => $end,
+        );
+
+    }
+
+    /**
+     * Parses the CALDAV:expand element
+     *
+     * @param \DOMElement $parentNode
+     * @return void
+     */
+    protected function parseExpand(\DOMElement $parentNode) {
+
+        $start = $parentNode->getAttribute('start');
+        if(!$start) {
+            throw new \OldSabre\DAV\Exception\BadRequest('The "start" attribute is required for the CALDAV:expand element');
+        }
+        $start = VObject\DateTimeParser::parseDateTime($start);
+
+        $end = $parentNode->getAttribute('end');
+        if(!$end) {
+            throw new \OldSabre\DAV\Exception\BadRequest('The "end" attribute is required for the CALDAV:expand element');
+        }
+
+        $end = VObject\DateTimeParser::parseDateTime($end);
+
+        if ($end <= $start) {
+            throw new \OldSabre\DAV\Exception\BadRequest('The end-date must be larger than the start-date in the expand element.');
+        }
+
+        return array(
+            'start' => $start,
+            'end' => $end,
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryValidator.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryValidator.php
new file mode 100644
index 0000000..581a126
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarQueryValidator.php
@@ -0,0 +1,392 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\VObject;
+use DateTime;
+
+/**
+ * CalendarQuery Validator
+ *
+ * This class is responsible for checking if an iCalendar object matches a set
+ * of filters. The main function to do this is 'validate'.
+ *
+ * This is used to determine which icalendar objects should be returned for a
+ * calendar-query REPORT request.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class CalendarQueryValidator {
+
+    /**
+     * Verify if a list of filters applies to the calendar data object
+     *
+     * The list of filters must be formatted as parsed by \OldSabre\CalDAV\CalendarQueryParser
+     *
+     * @param VObject\Component $vObject
+     * @param array $filters
+     * @return bool
+     */
+    public function validate(VObject\Component $vObject,array $filters) {
+
+        // The top level object is always a component filter.
+        // We'll parse it manually, as it's pretty simple.
+        if ($vObject->name !== $filters['name']) {
+            return false;
+        }
+
+        return
+            $this->validateCompFilters($vObject, $filters['comp-filters']) &&
+            $this->validatePropFilters($vObject, $filters['prop-filters']);
+
+
+    }
+
+    /**
+     * This method checks the validity of comp-filters.
+     *
+     * A list of comp-filters needs to be specified. Also the parent of the
+     * component we're checking should be specified, not the component to check
+     * itself.
+     *
+     * @param VObject\Component $parent
+     * @param array $filters
+     * @return bool
+     */
+    protected function validateCompFilters(VObject\Component $parent, array $filters) {
+
+        foreach($filters as $filter) {
+
+            $isDefined = isset($parent->$filter['name']);
+
+            if ($filter['is-not-defined']) {
+
+                if ($isDefined) {
+                    return false;
+                } else {
+                    continue;
+                }
+
+            }
+            if (!$isDefined) {
+                return false;
+            }
+
+            if ($filter['time-range']) {
+                foreach($parent->$filter['name'] as $subComponent) {
+                    if ($this->validateTimeRange($subComponent, $filter['time-range']['start'], $filter['time-range']['end'])) {
+                        continue 2;
+                    }
+                }
+                return false;
+            }
+
+            if (!$filter['comp-filters'] && !$filter['prop-filters']) {
+                continue;
+            }
+
+            // If there are sub-filters, we need to find at least one component
+            // for which the subfilters hold true.
+            foreach($parent->$filter['name'] as $subComponent) {
+
+                if (
+                    $this->validateCompFilters($subComponent, $filter['comp-filters']) &&
+                    $this->validatePropFilters($subComponent, $filter['prop-filters'])) {
+                        // We had a match, so this comp-filter succeeds
+                        continue 2;
+                }
+
+            }
+
+            // If we got here it means there were sub-comp-filters or
+            // sub-prop-filters and there was no match. This means this filter
+            // needs to return false.
+            return false;
+
+        }
+
+        // If we got here it means we got through all comp-filters alive so the
+        // filters were all true.
+        return true;
+
+    }
+
+    /**
+     * This method checks the validity of prop-filters.
+     *
+     * A list of prop-filters needs to be specified. Also the parent of the
+     * property we're checking should be specified, not the property to check
+     * itself.
+     *
+     * @param VObject\Component $parent
+     * @param array $filters
+     * @return bool
+     */
+    protected function validatePropFilters(VObject\Component $parent, array $filters) {
+
+        foreach($filters as $filter) {
+
+            $isDefined = isset($parent->$filter['name']);
+
+            if ($filter['is-not-defined']) {
+
+                if ($isDefined) {
+                    return false;
+                } else {
+                    continue;
+                }
+
+            }
+            if (!$isDefined) {
+                return false;
+            }
+
+            if ($filter['time-range']) {
+                foreach($parent->$filter['name'] as $subComponent) {
+                    if ($this->validateTimeRange($subComponent, $filter['time-range']['start'], $filter['time-range']['end'])) {
+                        continue 2;
+                    }
+                }
+                return false;
+            }
+
+            if (!$filter['param-filters'] && !$filter['text-match']) {
+                continue;
+            }
+
+            // If there are sub-filters, we need to find at least one property
+            // for which the subfilters hold true.
+            foreach($parent->$filter['name'] as $subComponent) {
+
+                if(
+                    $this->validateParamFilters($subComponent, $filter['param-filters']) &&
+                    (!$filter['text-match'] || $this->validateTextMatch($subComponent, $filter['text-match']))
+                ) {
+                    // We had a match, so this prop-filter succeeds
+                    continue 2;
+                }
+
+            }
+
+            // If we got here it means there were sub-param-filters or
+            // text-match filters and there was no match. This means the
+            // filter needs to return false.
+            return false;
+
+        }
+
+        // If we got here it means we got through all prop-filters alive so the
+        // filters were all true.
+        return true;
+
+    }
+
+    /**
+     * This method checks the validity of param-filters.
+     *
+     * A list of param-filters needs to be specified. Also the parent of the
+     * parameter we're checking should be specified, not the parameter to check
+     * itself.
+     *
+     * @param VObject\Property $parent
+     * @param array $filters
+     * @return bool
+     */
+    protected function validateParamFilters(VObject\Property $parent, array $filters) {
+
+        foreach($filters as $filter) {
+
+            $isDefined = isset($parent[$filter['name']]);
+
+            if ($filter['is-not-defined']) {
+
+                if ($isDefined) {
+                    return false;
+                } else {
+                    continue;
+                }
+
+            }
+            if (!$isDefined) {
+                return false;
+            }
+
+            if (!$filter['text-match']) {
+                continue;
+            }
+
+            if (version_compare(VObject\Version::VERSION, '3.0.0beta1', '>=')) {
+
+                // If there are sub-filters, we need to find at least one parameter
+                // for which the subfilters hold true.
+                foreach($parent[$filter['name']]->getParts() as $subParam) {
+
+                    if($this->validateTextMatch($subParam,$filter['text-match'])) {
+                        // We had a match, so this param-filter succeeds
+                        continue 2;
+                    }
+
+                }
+
+            } else {
+
+                // If there are sub-filters, we need to find at least one parameter
+                // for which the subfilters hold true.
+                foreach($parent[$filter['name']] as $subParam) {
+
+                    if($this->validateTextMatch($subParam,$filter['text-match'])) {
+                        // We had a match, so this param-filter succeeds
+                        continue 2;
+                    }
+
+                }
+
+            }
+
+            // If we got here it means there was a text-match filter and there
+            // were no matches. This means the filter needs to return false.
+            return false;
+
+        }
+
+        // If we got here it means we got through all param-filters alive so the
+        // filters were all true.
+        return true;
+
+    }
+
+    /**
+     * This method checks the validity of a text-match.
+     *
+     * A single text-match should be specified as well as the specific property
+     * or parameter we need to validate.
+     *
+     * @param VObject\Node|string $check Value to check against.
+     * @param array $textMatch
+     * @return bool
+     */
+    protected function validateTextMatch($check, array $textMatch) {
+
+        if ($check instanceof VObject\Node) {
+            $check = (string)$check;
+        }
+
+        $isMatching = \OldSabre\DAV\StringUtil::textMatch($check, $textMatch['value'], $textMatch['collation']);
+
+        return ($textMatch['negate-condition'] xor $isMatching);
+
+    }
+
+    /**
+     * Validates if a component matches the given time range.
+     *
+     * This is all based on the rules specified in rfc4791, which are quite
+     * complex.
+     *
+     * @param VObject\Node $component
+     * @param DateTime $start
+     * @param DateTime $end
+     * @return bool
+     */
+    protected function validateTimeRange(VObject\Node $component, $start, $end) {
+
+        if (is_null($start)) {
+            $start = new DateTime('1900-01-01');
+        }
+        if (is_null($end)) {
+            $end = new DateTime('3000-01-01');
+        }
+
+        switch($component->name) {
+
+            case 'VEVENT' :
+            case 'VTODO' :
+            case 'VJOURNAL' :
+
+                return $component->isInTimeRange($start, $end);
+
+            case 'VALARM' :
+
+                // If the valarm is wrapped in a recurring event, we need to
+                // expand the recursions, and validate each.
+                //
+                // Our datamodel doesn't easily allow us to do this straight
+                // in the VALARM component code, so this is a hack, and an
+                // expensive one too.
+                if ($component->parent->name === 'VEVENT' && $component->parent->RRULE) {
+
+                    // Fire up the iterator!
+                    $it = new VObject\RecurrenceIterator($component->parent->parent, (string)$component->parent->UID);
+                    while($it->valid()) {
+                        $expandedEvent = $it->getEventObject();
+
+                        // We need to check from these expanded alarms, which
+                        // one is the first to trigger. Based on this, we can
+                        // determine if we can 'give up' expanding events.
+                        $firstAlarm = null;
+                        if ($expandedEvent->VALARM !== null) {
+                            foreach($expandedEvent->VALARM as $expandedAlarm) {
+
+                                $effectiveTrigger = $expandedAlarm->getEffectiveTriggerTime();
+                                if ($expandedAlarm->isInTimeRange($start, $end)) {
+                                    return true;
+                                }
+
+                                if ((string)$expandedAlarm->TRIGGER['VALUE'] === 'DATE-TIME') {
+                                    // This is an alarm with a non-relative trigger
+                                    // time, likely created by a buggy client. The
+                                    // implication is that every alarm in this
+                                    // recurring event trigger at the exact same
+                                    // time. It doesn't make sense to traverse
+                                    // further.
+                                } else {
+                                    // We store the first alarm as a means to
+                                    // figure out when we can stop traversing.
+                                    if (!$firstAlarm || $effectiveTrigger < $firstAlarm) {
+                                        $firstAlarm = $effectiveTrigger;
+                                    }
+                                }
+                            }
+                        }
+                        if (is_null($firstAlarm)) {
+                            // No alarm was found.
+                            //
+                            // Or technically: No alarm that will change for
+                            // every instance of the recurrence was found,
+                            // which means we can assume there was no match.
+                            return false;
+                        }
+                        if ($firstAlarm > $end) {
+                            return false;
+                        }
+                        $it->next();
+                    }
+                    return false;
+                } else {
+                    return $component->isInTimeRange($start, $end);
+                }
+
+            case 'VFREEBUSY' :
+                throw new \OldSabre\DAV\Exception\NotImplemented('time-range filters are currently not supported on ' . $component->name . ' components');
+
+            case 'COMPLETED' :
+            case 'CREATED' :
+            case 'DTEND' :
+            case 'DTSTAMP' :
+            case 'DTSTART' :
+            case 'DUE' :
+            case 'LAST-MODIFIED' :
+                return ($start <= $component->getDateTime() && $end >= $component->getDateTime());
+
+
+
+            default :
+                throw new \OldSabre\DAV\Exception\BadRequest('You cannot create a time-range filter on a ' . $component->name . ' component');
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarRootNode.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarRootNode.php
new file mode 100644
index 0000000..810a249
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/CalendarRootNode.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAVACL\PrincipalBackend;
+
+/**
+ * Calendars collection
+ *
+ * This object is responsible for generating a list of calendar-homes for each
+ * user.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class CalendarRootNode extends \OldSabre\DAVACL\AbstractPrincipalCollection {
+
+    /**
+     * CalDAV backend
+     *
+     * @var OldSabre\CalDAV\Backend\BackendInterface
+     */
+    protected $caldavBackend;
+
+    /**
+     * Constructor
+     *
+     * This constructor needs both an authentication and a caldav backend.
+     *
+     * By default this class will show a list of calendar collections for
+     * principals in the 'principals' collection. If your main principals are
+     * actually located in a different path, use the $principalPrefix argument
+     * to override this.
+     *
+     * @param PrincipalBackend\BackendInterface $principalBackend
+     * @param Backend\BackendInterface $caldavBackend
+     * @param string $principalPrefix
+     */
+    public function __construct(PrincipalBackend\BackendInterface $principalBackend,Backend\BackendInterface $caldavBackend, $principalPrefix = 'principals') {
+
+        parent::__construct($principalBackend, $principalPrefix);
+        $this->caldavBackend = $caldavBackend;
+
+    }
+
+    /**
+     * Returns the nodename
+     *
+     * We're overriding this, because the default will be the 'principalPrefix',
+     * and we want it to be OldSabre\CalDAV\Plugin::CALENDAR_ROOT
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return Plugin::CALENDAR_ROOT;
+
+    }
+
+    /**
+     * This method returns a node for a principal.
+     *
+     * The passed array contains principal information, and is guaranteed to
+     * at least contain a uri item. Other properties may or may not be
+     * supplied by the authentication backend.
+     *
+     * @param array $principal
+     * @return \OldSabre\DAV\INode
+     */
+    public function getChildForPrincipal(array $principal) {
+
+        return new UserCalendars($this->caldavBackend, $principal);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Exception/InvalidComponentType.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Exception/InvalidComponentType.php
new file mode 100644
index 0000000..c335fcd
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Exception/InvalidComponentType.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace OldSabre\CalDAV\Exception;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * InvalidComponentType
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class InvalidComponentType extends DAV\Exception\Forbidden {
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {CALDAV:}supported-calendar-component as defined in rfc4791
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS(CalDAV\Plugin::NS_CALDAV,'cal:supported-calendar-component');
+        $errorNode->appendChild($np);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICSExportPlugin.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICSExportPlugin.php
new file mode 100644
index 0000000..4a5a75b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICSExportPlugin.php
@@ -0,0 +1,142 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAV;
+use OldSabre\VObject;
+
+/**
+ * ICS Exporter
+ *
+ * This plugin adds the ability to export entire calendars as .ics files.
+ * This is useful for clients that don't support CalDAV yet. They often do
+ * support ics files.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ICSExportPlugin extends DAV\ServerPlugin {
+
+    /**
+     * Reference to Server class
+     *
+     * @var \OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin and registers event handlers
+     *
+     * @param \OldSabre\DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'beforeMethod'), 90);
+
+    }
+
+    /**
+     * 'beforeMethod' event handles. This event handles intercepts GET requests ending
+     * with ?export
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        if ($method!='GET') return;
+        if ($this->server->httpRequest->getQueryString()!='export') return;
+
+        // splitting uri
+        list($uri) = explode('?',$uri,2);
+
+        $node = $this->server->tree->getNodeForPath($uri);
+
+        if (!($node instanceof Calendar)) return;
+
+        // Checking ACL, if available.
+        if ($aclPlugin = $this->server->getPlugin('acl')) {
+            $aclPlugin->checkPrivileges($uri, '{DAV:}read');
+        }
+
+        $this->server->httpResponse->setHeader('Content-Type','text/calendar');
+        $this->server->httpResponse->sendStatus(200);
+
+        $nodes = $this->server->getPropertiesForPath($uri, array(
+            '{' . Plugin::NS_CALDAV . '}calendar-data',
+        ),1);
+
+        $this->server->httpResponse->sendBody($this->generateICS($nodes));
+
+        // Returning false to break the event chain
+        return false;
+
+    }
+
+    /**
+     * Merges all calendar objects, and builds one big ics export
+     *
+     * @param array $nodes
+     * @return string
+     */
+    public function generateICS(array $nodes) {
+
+        $calendar = new VObject\Component\VCalendar();
+        $calendar->version = '2.0';
+        if (DAV\Server::$exposeVersion) {
+            $calendar->prodid = '-//SabreDAV//SabreDAV ' . DAV\Version::VERSION . '//EN';
+        } else {
+            $calendar->prodid = '-//SabreDAV//SabreDAV//EN';
+        }
+        $calendar->calscale = 'GREGORIAN';
+
+        $collectedTimezones = array();
+
+        $timezones = array();
+        $objects = array();
+
+        foreach($nodes as $node) {
+
+            if (!isset($node[200]['{' . Plugin::NS_CALDAV . '}calendar-data'])) {
+                continue;
+            }
+            $nodeData = $node[200]['{' . Plugin::NS_CALDAV . '}calendar-data'];
+
+            $nodeComp = VObject\Reader::read($nodeData);
+
+            foreach($nodeComp->children() as $child) {
+
+                switch($child->name) {
+                    case 'VEVENT' :
+                    case 'VTODO' :
+                    case 'VJOURNAL' :
+                        $objects[] = $child;
+                        break;
+
+                    // VTIMEZONE is special, because we need to filter out the duplicates
+                    case 'VTIMEZONE' :
+                        // Naively just checking tzid.
+                        if (in_array((string)$child->TZID, $collectedTimezones)) continue;
+
+                        $timezones[] = $child;
+                        $collectedTimezones[] = $child->TZID;
+                        break;
+
+                }
+
+            }
+
+        }
+
+        foreach($timezones as $tz) $calendar->add($tz);
+        foreach($objects as $obj) $calendar->add($obj);
+
+        return $calendar->serialize();
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendar.php
new file mode 100644
index 0000000..70916bc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendar.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace OldSabre\CalDAV;
+use OldSabre\DAV;
+
+/**
+ * Calendar interface
+ *
+ * Implement this interface to allow a node to be recognized as an calendar.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ICalendar extends DAV\ICollection {
+
+    /**
+     * Performs a calendar-query on the contents of this calendar.
+     *
+     * The calendar-query is defined in RFC4791 : CalDAV. Using the
+     * calendar-query it is possible for a client to request a specific set of
+     * object, based on contents of iCalendar properties, date-ranges and
+     * iCalendar component types (VTODO, VEVENT).
+     *
+     * This method should just return a list of (relative) urls that match this
+     * query.
+     *
+     * The list of filters are specified as an array. The exact array is
+     * documented by \OldSabre\CalDAV\CalendarQueryParser.
+     *
+     * @param array $filters
+     * @return array
+     */
+    public function calendarQuery(array $filters);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendarObject.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendarObject.php
new file mode 100644
index 0000000..4e5dcd7
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ICalendarObject.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace OldSabre\CalDAV;
+use OldSabre\DAV;
+
+/**
+ * CalendarObject interface
+ *
+ * Extend the ICalendarObject interface to allow your custom nodes to be picked up as
+ * CalendarObjects.
+ *
+ * Calendar objects are resources such as Events, Todo's or Journals.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ICalendarObject extends DAV\IFile {
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/IShareableCalendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/IShareableCalendar.php
new file mode 100644
index 0000000..c8fed62
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/IShareableCalendar.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+/**
+ * This interface represents a Calendar that can be shared with other users.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IShareableCalendar extends ICalendar {
+
+    /**
+     * Updates the list of shares.
+     *
+     * The first array is a list of people that are to be added to the
+     * calendar.
+     *
+     * Every element in the add array has the following properties:
+     *   * href - A url. Usually a mailto: address
+     *   * commonName - Usually a first and last name, or false
+     *   * summary - A description of the share, can also be false
+     *   * readOnly - A boolean value
+     *
+     * Every element in the remove array is just the address string.
+     *
+     * @param array $add
+     * @param array $remove
+     * @return void
+     */
+    function updateShares(array $add, array $remove);
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the OldSabre\CalDAV\SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * @return array
+     */
+    function getShares();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ISharedCalendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ISharedCalendar.php
new file mode 100644
index 0000000..05ebe79
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ISharedCalendar.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+/**
+ * This interface represents a Calendar that is shared by a different user.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ISharedCalendar extends ICalendar {
+
+    /**
+     * This method should return the url of the owners' copy of the shared
+     * calendar.
+     *
+     * @return string
+     */
+    function getSharedUrl();
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the OldSabre\CalDAV\SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * @return array
+     */
+    function getShares();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Collection.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Collection.php
new file mode 100644
index 0000000..d18a409
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Collection.php
@@ -0,0 +1,173 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+use OldSabre\DAVACL;
+
+/**
+ * This node represents a list of notifications.
+ *
+ * It provides no additional functionality, but you must implement this
+ * interface to allow the Notifications plugin to mark the collection
+ * as a notifications collection.
+ *
+ * This collection should only return OldSabre\CalDAV\Notifications\INode nodes as
+ * its children.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Collection extends DAV\Collection implements ICollection, DAVACL\IACL {
+
+    /**
+     * The notification backend
+     *
+     * @var OldSabre\CalDAV\Backend\NotificationSupport
+     */
+    protected $caldavBackend;
+
+    /**
+     * Principal uri
+     *
+     * @var string
+     */
+    protected $principalUri;
+
+    /**
+     * Constructor
+     *
+     * @param CalDAV\Backend\NotificationSupport $caldavBackend
+     * @param string $principalUri
+     */
+    public function __construct(CalDAV\Backend\NotificationSupport $caldavBackend, $principalUri) {
+
+        $this->caldavBackend = $caldavBackend;
+        $this->principalUri = $principalUri;
+
+    }
+
+    /**
+     * Returns all notifications for a principal
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        $children = array();
+        $notifications = $this->caldavBackend->getNotificationsForPrincipal($this->principalUri);
+
+        foreach($notifications as $notification) {
+
+            $children[] = new Node(
+                $this->caldavBackend,
+                $this->principalUri,
+                $notification
+            );
+        }
+
+        return $children;
+
+    }
+
+    /**
+     * Returns the name of this object
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return 'notifications';
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalUri;
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'principal' => $this->getOwner(),
+                'privilege' => '{DAV:}read',
+                'protected' => true,
+            ),
+            array(
+                'principal' => $this->getOwner(),
+                'privilege' => '{DAV:}write',
+                'protected' => true,
+            )
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's as an array argument.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\NotImplemented('Updating ACLs is not implemented here');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/ICollection.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/ICollection.php
new file mode 100644
index 0000000..cabdac4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/ICollection.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications;
+
+use OldSabre\DAV;
+
+/**
+ * This node represents a list of notifications.
+ *
+ * It provides no additional functionality, but you must implement this
+ * interface to allow the Notifications plugin to mark the collection
+ * as a notifications collection.
+ *
+ * This collection should only return OldSabre\CalDAV\Notifications\INode nodes as
+ * its children.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ICollection extends DAV\ICollection {
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INode.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INode.php
new file mode 100644
index 0000000..f63f8cc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INode.php
@@ -0,0 +1,38 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications;
+
+/**
+ * This node represents a single notification.
+ *
+ * The signature is mostly identical to that of OldSabre\DAV\IFile, but the get() method
+ * MUST return an xml document that matches the requirements of the
+ * 'caldav-notifications.txt' spec.
+ *
+ * For a complete example, check out the Notification class, which contains
+ * some helper functions.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface INode {
+
+    /**
+     * This method must return an xml element, using the
+     * OldSabre\CalDAV\Notifications\INotificationType classes.
+     *
+     * @return INotificationType
+     */
+    function getNotificationType();
+
+    /**
+     * Returns the etag for the notification.
+     *
+     * The etag must be surrounded by litteral double-quotes.
+     *
+     * @return string
+     */
+    function getETag();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INotificationType.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INotificationType.php
new file mode 100644
index 0000000..ef3b3e9
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/INotificationType.php
@@ -0,0 +1,44 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications;
+use OldSabre\DAV;
+
+/**
+ * This interface reflects a single notification type.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface INotificationType extends DAV\PropertyInterface {
+
+    /**
+     * This method serializes the entire notification, as it is used in the
+     * response body.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    function serializeBody(DAV\Server $server, \DOMElement $node);
+
+    /**
+     * Returns a unique id for this notification
+     *
+     * This is just the base url. This should generally be some kind of unique
+     * id.
+     *
+     * @return string
+     */
+    function getId();
+
+    /**
+     * Returns the ETag for this notification.
+     *
+     * The ETag must be surrounded by literal double-quotes.
+     *
+     * @return string
+     */
+    function getETag();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Node.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Node.php
new file mode 100644
index 0000000..c9b88a4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Node.php
@@ -0,0 +1,192 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+use OldSabre\DAVACL;
+
+/**
+ * This node represents a single notification.
+ *
+ * The signature is mostly identical to that of OldSabre\DAV\IFile, but the get() method
+ * MUST return an xml document that matches the requirements of the
+ * 'caldav-notifications.txt' spec.
+
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Node extends DAV\File implements INode, DAVACL\IACL {
+
+    /**
+     * The notification backend
+     *
+     * @var OldSabre\CalDAV\Backend\NotificationSupport
+     */
+    protected $caldavBackend;
+
+    /**
+     * The actual notification
+     *
+     * @var OldSabre\CalDAV\Notifications\INotificationType
+     */
+    protected $notification;
+
+    /**
+     * Owner principal of the notification
+     *
+     * @var string
+     */
+    protected $principalUri;
+
+    /**
+     * Constructor
+     *
+     * @param CalDAV\Backend\NotificationSupport $caldavBackend
+     * @param string $principalUri
+     * @param CalDAV\Notifications\INotificationType $notification
+     */
+    public function __construct(CalDAV\Backend\NotificationSupport $caldavBackend, $principalUri, INotificationType $notification) {
+
+        $this->caldavBackend = $caldavBackend;
+        $this->principalUri = $principalUri;
+        $this->notification = $notification;
+
+    }
+
+    /**
+     * Returns the path name for this notification
+     *
+     * @return id
+     */
+    public function getName() {
+
+        return $this->notification->getId() . '.xml';
+
+    }
+
+    /**
+     * Returns the etag for the notification.
+     *
+     * The etag must be surrounded by litteral double-quotes.
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        return $this->notification->getETag();
+
+    }
+
+    /**
+     * This method must return an xml element, using the
+     * OldSabre\CalDAV\Notifications\INotificationType classes.
+     *
+     * @return INotificationType
+     */
+    public function getNotificationType() {
+
+        return $this->notification;
+
+    }
+
+    /**
+     * Deletes this notification
+     *
+     * @return void
+     */
+    public function delete() {
+
+        $this->caldavBackend->deleteNotification($this->getOwner(), $this->notification);
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalUri;
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'principal' => $this->getOwner(),
+                'privilege' => '{DAV:}read',
+                'protected' => true,
+            ),
+            array(
+                'principal' => $this->getOwner(),
+                'privilege' => '{DAV:}write',
+                'protected' => true,
+            )
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's as an array argument.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\NotImplemented('Updating ACLs is not implemented here');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/Invite.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/Invite.php
new file mode 100644
index 0000000..3c8fbf5
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/Invite.php
@@ -0,0 +1,324 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications\Notification;
+
+use OldSabre\CalDAV\SharingPlugin as SharingPlugin;
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * This class represents the cs:invite-notification notification element.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Invite extends DAV\Property implements CalDAV\Notifications\INotificationType {
+
+    /**
+     * A unique id for the message
+     *
+     * @var string
+     */
+    protected $id;
+
+    /**
+     * Timestamp of the notification
+     *
+     * @var DateTime
+     */
+    protected $dtStamp;
+
+    /**
+     * A url to the recipient of the notification. This can be an email
+     * address (mailto:), or a principal url.
+     *
+     * @var string
+     */
+    protected $href;
+
+    /**
+     * The type of message, see the SharingPlugin::STATUS_* constants.
+     *
+     * @var int
+     */
+    protected $type;
+
+    /**
+     * True if access to a calendar is read-only.
+     *
+     * @var bool
+     */
+    protected $readOnly;
+
+    /**
+     * A url to the shared calendar.
+     *
+     * @var string
+     */
+    protected $hostUrl;
+
+    /**
+     * Url to the sharer of the calendar
+     *
+     * @var string
+     */
+    protected $organizer;
+
+    /**
+     * The name of the sharer.
+     *
+     * @var string
+     */
+    protected $commonName;
+
+    /**
+     * The name of the sharer.
+     *
+     * @var string
+     */
+    protected $firstName;
+
+    /**
+     * The name of the sharer.
+     *
+     * @var string
+     */
+    protected $lastName;
+
+    /**
+     * A description of the share request
+     *
+     * @var string
+     */
+    protected $summary;
+
+    /**
+     * The Etag for the notification
+     *
+     * @var string
+     */
+    protected $etag;
+
+    /**
+     * The list of supported components
+     *
+     * @var OldSabre\CalDAV\Property\SupportedCalendarComponentSet
+     */
+    protected $supportedComponents;
+
+    /**
+     * Creates the Invite notification.
+     *
+     * This constructor receives an array with the following elements:
+     *
+     *   * id           - A unique id
+     *   * etag         - The etag
+     *   * dtStamp      - A DateTime object with a timestamp for the notification.
+     *   * type         - The type of notification, see SharingPlugin::STATUS_*
+     *                    constants for details.
+     *   * readOnly     - This must be set to true, if this is an invite for
+     *                    read-only access to a calendar.
+     *   * hostUrl      - A url to the shared calendar.
+     *   * organizer    - Url to the sharer principal.
+     *   * commonName   - The real name of the sharer (optional).
+     *   * firstName    - The first name of the sharer (optional).
+     *   * lastName     - The last name of the sharer (optional).
+     *   * summary      - Description of the share, can be the same as the
+     *                    calendar, but may also be modified (optional).
+     *   * supportedComponents - An instance of
+     *                    OldSabre\CalDAV\Property\SupportedCalendarComponentSet.
+     *                    This allows the client to determine which components
+     *                    will be supported in the shared calendar. This is
+     *                    also optional.
+     *
+     * @param array $values All the options
+     */
+    public function __construct(array $values) {
+
+        $required = array(
+            'id',
+            'etag',
+            'href',
+            'dtStamp',
+            'type',
+            'readOnly',
+            'hostUrl',
+            'organizer',
+        );
+        foreach($required as $item) {
+            if (!isset($values[$item])) {
+                throw new \InvalidArgumentException($item . ' is a required constructor option');
+            }
+        }
+
+        foreach($values as $key=>$value) {
+            if (!property_exists($this, $key)) {
+                throw new \InvalidArgumentException('Unknown option: ' . $key);
+            }
+            $this->$key = $value;
+        }
+
+    }
+
+    /**
+     * Serializes the notification as a single property.
+     *
+     * You should usually just encode the single top-level element of the
+     * notification.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $node) {
+
+        $prop = $node->ownerDocument->createElement('cs:invite-notification');
+        $node->appendChild($prop);
+
+    }
+
+    /**
+     * This method serializes the entire notification, as it is used in the
+     * response body.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serializeBody(DAV\Server $server, \DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+
+        $dt = $doc->createElement('cs:dtstamp');
+        $this->dtStamp->setTimezone(new \DateTimezone('GMT'));
+        $dt->appendChild($doc->createTextNode($this->dtStamp->format('Ymd\\THis\\Z')));
+        $node->appendChild($dt);
+
+        $prop = $doc->createElement('cs:invite-notification');
+        $node->appendChild($prop);
+
+        $uid = $doc->createElement('cs:uid');
+        $uid->appendChild( $doc->createTextNode($this->id) );
+        $prop->appendChild($uid);
+
+        $href = $doc->createElement('d:href');
+        $href->appendChild( $doc->createTextNode( $this->href ) );
+        $prop->appendChild($href);
+
+        $nodeName = null;
+        switch($this->type) {
+
+            case SharingPlugin::STATUS_ACCEPTED :
+                $nodeName = 'cs:invite-accepted';
+                break;
+            case SharingPlugin::STATUS_DECLINED :
+                $nodeName = 'cs:invite-declined';
+                break;
+            case SharingPlugin::STATUS_DELETED :
+                $nodeName = 'cs:invite-deleted';
+                break;
+            case SharingPlugin::STATUS_NORESPONSE :
+                $nodeName = 'cs:invite-noresponse';
+                break;
+
+        }
+        $prop->appendChild(
+            $doc->createElement($nodeName)
+        );
+        $hostHref = $doc->createElement('d:href', $server->getBaseUri() . $this->hostUrl);
+        $hostUrl  = $doc->createElement('cs:hosturl');
+        $hostUrl->appendChild($hostHref);
+        $prop->appendChild($hostUrl);
+
+        $access = $doc->createElement('cs:access');
+        if ($this->readOnly) {
+            $access->appendChild($doc->createElement('cs:read'));
+        } else {
+            $access->appendChild($doc->createElement('cs:read-write'));
+        }
+        $prop->appendChild($access);
+
+        $organizerUrl  = $doc->createElement('cs:organizer');
+        // If the organizer contains a 'mailto:' part, it means it should be
+        // treated as absolute.
+        if (strtolower(substr($this->organizer,0,7))==='mailto:') {
+            $organizerHref = new DAV\Property\Href($this->organizer, false);
+        } else {
+            $organizerHref = new DAV\Property\Href($this->organizer, true);
+        }
+        $organizerHref->serialize($server, $organizerUrl);
+
+        if ($this->commonName) {
+            $commonName = $doc->createElement('cs:common-name');
+            $commonName->appendChild($doc->createTextNode($this->commonName));
+            $organizerUrl->appendChild($commonName);
+
+            $commonNameOld = $doc->createElement('cs:organizer-cn');
+            $commonNameOld->appendChild($doc->createTextNode($this->commonName));
+            $prop->appendChild($commonNameOld);
+
+        }
+        if ($this->firstName) {
+            $firstName = $doc->createElement('cs:first-name');
+            $firstName->appendChild($doc->createTextNode($this->firstName));
+            $organizerUrl->appendChild($firstName);
+
+            $firstNameOld = $doc->createElement('cs:organizer-first');
+            $firstNameOld->appendChild($doc->createTextNode($this->firstName));
+            $prop->appendChild($firstNameOld);
+        }
+        if ($this->lastName) {
+            $lastName = $doc->createElement('cs:last-name');
+            $lastName->appendChild($doc->createTextNode($this->lastName));
+            $organizerUrl->appendChild($lastName);
+
+            $lastNameOld = $doc->createElement('cs:organizer-last');
+            $lastNameOld->appendChild($doc->createTextNode($this->lastName));
+            $prop->appendChild($lastNameOld);
+        }
+        $prop->appendChild($organizerUrl);
+
+        if ($this->summary) {
+            $summary = $doc->createElement('cs:summary');
+            $summary->appendChild($doc->createTextNode($this->summary));
+            $prop->appendChild($summary);
+        }
+        if ($this->supportedComponents) {
+
+            $xcomp = $doc->createElement('cal:supported-calendar-component-set');
+            $this->supportedComponents->serialize($server, $xcomp);
+            $prop->appendChild($xcomp);
+
+        }
+
+    }
+
+    /**
+     * Returns a unique id for this notification
+     *
+     * This is just the base url. This should generally be some kind of unique
+     * id.
+     *
+     * @return string
+     */
+    public function getId() {
+
+        return $this->id;
+
+    }
+
+    /**
+     * Returns the ETag for this notification.
+     *
+     * The ETag must be surrounded by literal double-quotes.
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        return $this->etag;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/InviteReply.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/InviteReply.php
new file mode 100644
index 0000000..540da86
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/InviteReply.php
@@ -0,0 +1,218 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications\Notification;
+
+use OldSabre\CalDAV\SharingPlugin as SharingPlugin;
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * This class represents the cs:invite-reply notification element.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class InviteReply extends DAV\Property implements CalDAV\Notifications\INotificationType {
+
+    /**
+     * A unique id for the message
+     *
+     * @var string
+     */
+    protected $id;
+
+    /**
+     * Timestamp of the notification
+     *
+     * @var DateTime
+     */
+    protected $dtStamp;
+
+    /**
+     * The unique id of the notification this was a reply to.
+     *
+     * @var string
+     */
+    protected $inReplyTo;
+
+    /**
+     * A url to the recipient of the original (!) notification.
+     *
+     * @var string
+     */
+    protected $href;
+
+    /**
+     * The type of message, see the SharingPlugin::STATUS_ constants.
+     *
+     * @var int
+     */
+    protected $type;
+
+    /**
+     * A url to the shared calendar.
+     *
+     * @var string
+     */
+    protected $hostUrl;
+
+    /**
+     * A description of the share request
+     *
+     * @var string
+     */
+    protected $summary;
+
+    /**
+     * Notification Etag
+     *
+     * @var string
+     */
+    protected $etag;
+
+    /**
+     * Creates the Invite Reply Notification.
+     *
+     * This constructor receives an array with the following elements:
+     *
+     *   * id           - A unique id
+     *   * etag         - The etag
+     *   * dtStamp      - A DateTime object with a timestamp for the notification.
+     *   * inReplyTo    - This should refer to the 'id' of the notification
+     *                    this is a reply to.
+     *   * type         - The type of notification, see SharingPlugin::STATUS_*
+     *                    constants for details.
+     *   * hostUrl      - A url to the shared calendar.
+     *   * summary      - Description of the share, can be the same as the
+     *                    calendar, but may also be modified (optional).
+     */
+    public function __construct(array $values) {
+
+        $required = array(
+            'id',
+            'etag',
+            'href',
+            'dtStamp',
+            'inReplyTo',
+            'type',
+            'hostUrl',
+        );
+        foreach($required as $item) {
+            if (!isset($values[$item])) {
+                throw new \InvalidArgumentException($item . ' is a required constructor option');
+            }
+        }
+
+        foreach($values as $key=>$value) {
+            if (!property_exists($this, $key)) {
+                throw new \InvalidArgumentException('Unknown option: ' . $key);
+            }
+            $this->$key = $value;
+        }
+
+    }
+
+    /**
+     * Serializes the notification as a single property.
+     *
+     * You should usually just encode the single top-level element of the
+     * notification.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $node) {
+
+        $prop = $node->ownerDocument->createElement('cs:invite-reply');
+        $node->appendChild($prop);
+
+    }
+
+    /**
+     * This method serializes the entire notification, as it is used in the
+     * response body.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serializeBody(DAV\Server $server, \DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+
+        $dt = $doc->createElement('cs:dtstamp');
+        $this->dtStamp->setTimezone(new \DateTimezone('GMT'));
+        $dt->appendChild($doc->createTextNode($this->dtStamp->format('Ymd\\THis\\Z')));
+        $node->appendChild($dt);
+
+        $prop = $doc->createElement('cs:invite-reply');
+        $node->appendChild($prop);
+
+        $uid = $doc->createElement('cs:uid');
+        $uid->appendChild($doc->createTextNode($this->id));
+        $prop->appendChild($uid);
+
+        $inReplyTo = $doc->createElement('cs:in-reply-to');
+        $inReplyTo->appendChild( $doc->createTextNode($this->inReplyTo) );
+        $prop->appendChild($inReplyTo);
+
+        $href = $doc->createElement('d:href');
+        $href->appendChild( $doc->createTextNode($this->href) );
+        $prop->appendChild($href);
+
+        $nodeName = null;
+        switch($this->type) {
+
+            case SharingPlugin::STATUS_ACCEPTED :
+                $nodeName = 'cs:invite-accepted';
+                break;
+            case SharingPlugin::STATUS_DECLINED :
+                $nodeName = 'cs:invite-declined';
+                break;
+
+        }
+        $prop->appendChild(
+            $doc->createElement($nodeName)
+        );
+        $hostHref = $doc->createElement('d:href', $server->getBaseUri() . $this->hostUrl);
+        $hostUrl  = $doc->createElement('cs:hosturl');
+        $hostUrl->appendChild($hostHref);
+        $prop->appendChild($hostUrl);
+
+        if ($this->summary) {
+            $summary = $doc->createElement('cs:summary');
+            $summary->appendChild($doc->createTextNode($this->summary));
+            $prop->appendChild($summary);
+        }
+
+    }
+
+    /**
+     * Returns a unique id for this notification
+     *
+     * This is just the base url. This should generally be some kind of unique
+     * id.
+     *
+     * @return string
+     */
+    public function getId() {
+
+        return $this->id;
+
+    }
+
+    /**
+     * Returns the ETag for this notification.
+     *
+     * The ETag must be surrounded by literal double-quotes.
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        return $this->etag;
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/SystemStatus.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/SystemStatus.php
new file mode 100644
index 0000000..aef0ea8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Notifications/Notification/SystemStatus.php
@@ -0,0 +1,182 @@
+<?php
+
+namespace OldSabre\CalDAV\Notifications\Notification;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * SystemStatus notification
+ *
+ * This notification can be used to indicate to the user that the system is
+ * down.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SystemStatus extends DAV\Property implements CalDAV\Notifications\INotificationType {
+
+    const TYPE_LOW = 1;
+    const TYPE_MEDIUM = 2;
+    const TYPE_HIGH = 3;
+
+    /**
+     * A unique id
+     *
+     * @var string
+     */
+    protected $id;
+
+    /**
+     * The type of alert. This should be one of the TYPE_ constants.
+     *
+     * @var int
+     */
+    protected $type;
+
+    /**
+     * A human-readable description of the problem.
+     *
+     * @var string
+     */
+    protected $description;
+
+    /**
+     * A url to a website with more information for the user.
+     *
+     * @var string
+     */
+    protected $href;
+
+    /**
+     * Notification Etag
+     *
+     * @var string
+     */
+    protected $etag;
+
+    /**
+     * Creates the notification.
+     *
+     * Some kind of unique id should be provided. This is used to generate a
+     * url.
+     *
+     * @param string $id
+     * @param string $etag
+     * @param int $type
+     * @param string $description
+     * @param string $href
+     */
+    public function __construct($id, $etag, $type = self::TYPE_HIGH, $description = null, $href = null) {
+
+        $this->id = $id;
+        $this->type = $type;
+        $this->description = $description;
+        $this->href = $href;
+        $this->etag = $etag;
+
+    }
+
+    /**
+     * Serializes the notification as a single property.
+     *
+     * You should usually just encode the single top-level element of the
+     * notification.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $node) {
+
+        switch($this->type) {
+            case self::TYPE_LOW :
+                $type = 'low';
+                break;
+            case self::TYPE_MEDIUM :
+                $type = 'medium';
+                break;
+            default :
+            case self::TYPE_HIGH :
+                $type = 'high';
+                break;
+        }
+
+        $prop = $node->ownerDocument->createElement('cs:systemstatus');
+        $prop->setAttribute('type', $type);
+
+        $node->appendChild($prop);
+
+    }
+
+    /**
+     * This method serializes the entire notification, as it is used in the
+     * response body.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serializeBody(DAV\Server $server, \DOMElement $node) {
+
+        switch($this->type) {
+            case self::TYPE_LOW :
+                $type = 'low';
+                break;
+            case self::TYPE_MEDIUM :
+                $type = 'medium';
+                break;
+            default :
+            case self::TYPE_HIGH :
+                $type = 'high';
+                break;
+        }
+
+        $prop = $node->ownerDocument->createElement('cs:systemstatus');
+        $prop->setAttribute('type', $type);
+
+        if ($this->description) {
+            $text = $node->ownerDocument->createTextNode($this->description);
+            $desc = $node->ownerDocument->createElement('cs:description');
+            $desc->appendChild($text);
+            $prop->appendChild($desc);
+        }
+        if ($this->href) {
+            $text = $node->ownerDocument->createTextNode($this->href);
+            $href = $node->ownerDocument->createElement('d:href');
+            $href->appendChild($text);
+            $prop->appendChild($href);
+        }
+
+        $node->appendChild($prop);
+
+    }
+
+    /**
+     * Returns a unique id for this notification
+     *
+     * This is just the base url. This should generally be some kind of unique
+     * id.
+     *
+     * @return string
+     */
+    public function getId() {
+
+        return $this->id;
+
+    }
+
+    /*
+     * Returns the ETag for this notification.
+     *
+     * The ETag must be surrounded by literal double-quotes.
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        return $this->etag;
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Plugin.php
new file mode 100644
index 0000000..8d9a279
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Plugin.php
@@ -0,0 +1,1338 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+use OldSabre\VObject;
+
+/**
+ * CalDAV plugin
+ *
+ * This plugin provides functionality added by CalDAV (RFC 4791)
+ * It implements new reports, and the MKCALENDAR method.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * This is the official CalDAV namespace
+     */
+    const NS_CALDAV = 'urn:ietf:params:xml:ns:caldav';
+
+    /**
+     * This is the namespace for the proprietary calendarserver extensions
+     */
+    const NS_CALENDARSERVER = 'http://calendarserver.org/ns/';
+
+    /**
+     * The hardcoded root for calendar objects. It is unfortunate
+     * that we're stuck with it, but it will have to do for now
+     */
+    const CALENDAR_ROOT = 'calendars';
+
+    /**
+     * Reference to server object
+     *
+     * @var DAV\Server
+     */
+    protected $server;
+
+    /**
+     * The email handler for invites and other scheduling messages.
+     *
+     * @var Schedule\IMip
+     */
+    protected $imipHandler;
+
+    /**
+     * Sets the iMIP handler.
+     *
+     * iMIP = The email transport of iCalendar scheduling messages. Setting
+     * this is optional, but if you want the server to allow invites to be sent
+     * out, you must set a handler.
+     *
+     * Specifically iCal will plain assume that the server supports this. If
+     * the server doesn't, iCal will display errors when inviting people to
+     * events.
+     *
+     * @param Schedule\IMip $imipHandler
+     * @return void
+     */
+    public function setIMipHandler(Schedule\IMip $imipHandler) {
+
+        $this->imipHandler = $imipHandler;
+
+    }
+
+    /**
+     * Use this method to tell the server this plugin defines additional
+     * HTTP methods.
+     *
+     * This method is passed a uri. It should only return HTTP methods that are
+     * available for the specified uri.
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getHTTPMethods($uri) {
+
+        // The MKCALENDAR is only available on unmapped uri's, whose
+        // parents extend IExtendedCollection
+        list($parent, $name) = DAV\URLUtil::splitPath($uri);
+
+        $node = $this->server->tree->getNodeForPath($parent);
+
+        if ($node instanceof DAV\IExtendedCollection) {
+            try {
+                $node->getChild($name);
+            } catch (DAV\Exception\NotFound $e) {
+                return array('MKCALENDAR');
+            }
+        }
+        return array();
+
+    }
+
+    /**
+     * Returns a list of features for the DAV: HTTP header.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array('calendar-access', 'calendar-proxy');
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'caldav';
+
+    }
+
+    /**
+     * Returns a list of reports this plugin supports.
+     *
+     * This will be used in the {DAV:}supported-report-set property.
+     * Note that you still need to subscribe to the 'report' event to actually
+     * implement them
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getSupportedReportSet($uri) {
+
+        $node = $this->server->tree->getNodeForPath($uri);
+
+        $reports = array();
+        if ($node instanceof ICalendar || $node instanceof ICalendarObject) {
+            $reports[] = '{' . self::NS_CALDAV . '}calendar-multiget';
+            $reports[] = '{' . self::NS_CALDAV . '}calendar-query';
+        }
+        if ($node instanceof ICalendar) {
+            $reports[] = '{' . self::NS_CALDAV . '}free-busy-query';
+        }
+        return $reports;
+
+    }
+
+    /**
+     * Initializes the plugin
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+
+        $server->subscribeEvent('unknownMethod',array($this,'unknownMethod'));
+        //$server->subscribeEvent('unknownMethod',array($this,'unknownMethod2'),1000);
+        $server->subscribeEvent('report',array($this,'report'));
+        $server->subscribeEvent('beforeGetProperties',array($this,'beforeGetProperties'));
+        $server->subscribeEvent('onHTMLActionsPanel', array($this,'htmlActionsPanel'));
+        $server->subscribeEvent('onBrowserPostAction', array($this,'browserPostAction'));
+        $server->subscribeEvent('beforeWriteContent', array($this, 'beforeWriteContent'));
+        $server->subscribeEvent('beforeCreateFile', array($this, 'beforeCreateFile'));
+        $server->subscribeEvent('beforeMethod', array($this,'beforeMethod'));
+
+        $server->xmlNamespaces[self::NS_CALDAV] = 'cal';
+        $server->xmlNamespaces[self::NS_CALENDARSERVER] = 'cs';
+
+        $server->propertyMap['{' . self::NS_CALDAV . '}supported-calendar-component-set'] = 'OldSabre\\CalDAV\\Property\\SupportedCalendarComponentSet';
+        $server->propertyMap['{' . self::NS_CALDAV . '}schedule-calendar-transp'] = 'OldSabre\\CalDAV\\Property\\ScheduleCalendarTransp';
+
+        $server->resourceTypeMapping['\\OldSabre\\CalDAV\\ICalendar'] = '{urn:ietf:params:xml:ns:caldav}calendar';
+        $server->resourceTypeMapping['\\OldSabre\\CalDAV\\Schedule\\IOutbox'] = '{urn:ietf:params:xml:ns:caldav}schedule-outbox';
+        $server->resourceTypeMapping['\\OldSabre\\CalDAV\\Principal\\IProxyRead'] = '{http://calendarserver.org/ns/}calendar-proxy-read';
+        $server->resourceTypeMapping['\\OldSabre\\CalDAV\\Principal\\IProxyWrite'] = '{http://calendarserver.org/ns/}calendar-proxy-write';
+        $server->resourceTypeMapping['\\OldSabre\\CalDAV\\Notifications\\ICollection'] = '{' . self::NS_CALENDARSERVER . '}notification';
+
+        array_push($server->protectedProperties,
+
+            '{' . self::NS_CALDAV . '}supported-calendar-component-set',
+            '{' . self::NS_CALDAV . '}supported-calendar-data',
+            '{' . self::NS_CALDAV . '}max-resource-size',
+            '{' . self::NS_CALDAV . '}min-date-time',
+            '{' . self::NS_CALDAV . '}max-date-time',
+            '{' . self::NS_CALDAV . '}max-instances',
+            '{' . self::NS_CALDAV . '}max-attendees-per-instance',
+            '{' . self::NS_CALDAV . '}calendar-home-set',
+            '{' . self::NS_CALDAV . '}supported-collation-set',
+            '{' . self::NS_CALDAV . '}calendar-data',
+
+            // scheduling extension
+            '{' . self::NS_CALDAV . '}schedule-inbox-URL',
+            '{' . self::NS_CALDAV . '}schedule-outbox-URL',
+            '{' . self::NS_CALDAV . '}calendar-user-address-set',
+            '{' . self::NS_CALDAV . '}calendar-user-type',
+
+            // CalendarServer extensions
+            '{' . self::NS_CALENDARSERVER . '}getctag',
+            '{' . self::NS_CALENDARSERVER . '}calendar-proxy-read-for',
+            '{' . self::NS_CALENDARSERVER . '}calendar-proxy-write-for',
+            '{' . self::NS_CALENDARSERVER . '}notification-URL',
+            '{' . self::NS_CALENDARSERVER . '}notificationtype'
+
+        );
+    }
+
+    /**
+     * This function handles support for the MKCALENDAR method
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function unknownMethod($method, $uri) {
+
+        switch ($method) {
+            case 'MKCALENDAR' :
+                $this->httpMkCalendar($uri);
+                // false is returned to stop the propagation of the
+                // unknownMethod event.
+                return false;
+            case 'POST' :
+
+                // Checking if this is a text/calendar content type
+                $contentType = $this->server->httpRequest->getHeader('Content-Type');
+                if (strpos($contentType, 'text/calendar')!==0) {
+                    return;
+                }
+
+                // Checking if we're talking to an outbox
+                try {
+                    $node = $this->server->tree->getNodeForPath($uri);
+                } catch (DAV\Exception\NotFound $e) {
+                    return;
+                }
+                if (!$node instanceof Schedule\IOutbox)
+                    return;
+
+                $this->outboxRequest($node, $uri);
+                return false;
+
+        }
+
+    }
+
+    /**
+     * This functions handles REPORT requests specific to CalDAV
+     *
+     * @param string $reportName
+     * @param \DOMNode $dom
+     * @return bool
+     */
+    public function report($reportName,$dom) {
+
+        switch($reportName) {
+            case '{'.self::NS_CALDAV.'}calendar-multiget' :
+                $this->calendarMultiGetReport($dom);
+                return false;
+            case '{'.self::NS_CALDAV.'}calendar-query' :
+                $this->calendarQueryReport($dom);
+                return false;
+            case '{'.self::NS_CALDAV.'}free-busy-query' :
+                $this->freeBusyQueryReport($dom);
+                return false;
+
+        }
+
+
+    }
+
+    /**
+     * This function handles the MKCALENDAR HTTP method, which creates
+     * a new calendar.
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function httpMkCalendar($uri) {
+
+        // Due to unforgivable bugs in iCal, we're completely disabling MKCALENDAR support
+        // for clients matching iCal in the user agent
+        //$ua = $this->server->httpRequest->getHeader('User-Agent');
+        //if (strpos($ua,'iCal/')!==false) {
+        //    throw new \OldSabre\DAV\Exception\Forbidden('iCal has major bugs in it\'s RFC3744 support. Therefore we are left with no other choice but disabling this feature.');
+        //}
+
+        $body = $this->server->httpRequest->getBody(true);
+        $properties = array();
+
+        if ($body) {
+
+            $dom = DAV\XMLUtil::loadDOMDocument($body);
+
+            foreach($dom->firstChild->childNodes as $child) {
+
+                if (DAV\XMLUtil::toClarkNotation($child)!=='{DAV:}set') continue;
+                foreach(DAV\XMLUtil::parseProperties($child,$this->server->propertyMap) as $k=>$prop) {
+                    $properties[$k] = $prop;
+                }
+
+            }
+        }
+
+        $resourceType = array('{DAV:}collection','{urn:ietf:params:xml:ns:caldav}calendar');
+
+        $this->server->createCollection($uri,$resourceType,$properties);
+
+        $this->server->httpResponse->sendStatus(201);
+        $this->server->httpResponse->setHeader('Content-Length',0);
+    }
+
+    /**
+     * beforeGetProperties
+     *
+     * This method handler is invoked before any after properties for a
+     * resource are fetched. This allows us to add in any CalDAV specific
+     * properties.
+     *
+     * @param string $path
+     * @param DAV\INode $node
+     * @param array $requestedProperties
+     * @param array $returnedProperties
+     * @return void
+     */
+    public function beforeGetProperties($path, DAV\INode $node, &$requestedProperties, &$returnedProperties) {
+
+        if ($node instanceof DAVACL\IPrincipal) {
+
+            // calendar-home-set property
+            $calHome = '{' . self::NS_CALDAV . '}calendar-home-set';
+            if (in_array($calHome,$requestedProperties)) {
+                $principalId = $node->getName();
+                $calendarHomePath = self::CALENDAR_ROOT . '/' . $principalId . '/';
+
+                unset($requestedProperties[array_search($calHome, $requestedProperties)]);
+                $returnedProperties[200][$calHome] = new DAV\Property\Href($calendarHomePath);
+
+            }
+
+            // schedule-outbox-URL property
+            $scheduleProp = '{' . self::NS_CALDAV . '}schedule-outbox-URL';
+            if (in_array($scheduleProp,$requestedProperties)) {
+                $principalId = $node->getName();
+                $outboxPath = self::CALENDAR_ROOT . '/' . $principalId . '/outbox';
+
+                unset($requestedProperties[array_search($scheduleProp, $requestedProperties)]);
+                $returnedProperties[200][$scheduleProp] = new DAV\Property\Href($outboxPath);
+
+            }
+
+            // calendar-user-address-set property
+            $calProp = '{' . self::NS_CALDAV . '}calendar-user-address-set';
+            if (in_array($calProp,$requestedProperties)) {
+
+                $addresses = $node->getAlternateUriSet();
+                $addresses[] = $this->server->getBaseUri() . DAV\URLUtil::encodePath($node->getPrincipalUrl() . '/');
+                unset($requestedProperties[array_search($calProp, $requestedProperties)]);
+                $returnedProperties[200][$calProp] = new DAV\Property\HrefList($addresses, false);
+
+            }
+
+            // These two properties are shortcuts for ical to easily find
+            // other principals this principal has access to.
+            $propRead = '{' . self::NS_CALENDARSERVER . '}calendar-proxy-read-for';
+            $propWrite = '{' . self::NS_CALENDARSERVER . '}calendar-proxy-write-for';
+            if (in_array($propRead,$requestedProperties) || in_array($propWrite,$requestedProperties)) {
+
+                $aclPlugin = $this->server->getPlugin('acl');
+                $membership = $aclPlugin->getPrincipalMembership($path);
+                $readList = array();
+                $writeList = array();
+
+                foreach($membership as $group) {
+
+                    $groupNode = $this->server->tree->getNodeForPath($group);
+
+                    // If the node is either ap proxy-read or proxy-write
+                    // group, we grab the parent principal and add it to the
+                    // list.
+                    if ($groupNode instanceof Principal\IProxyRead) {
+                        list($readList[]) = DAV\URLUtil::splitPath($group);
+                    }
+                    if ($groupNode instanceof Principal\IProxyWrite) {
+                        list($writeList[]) = DAV\URLUtil::splitPath($group);
+                    }
+
+                }
+                if (in_array($propRead,$requestedProperties)) {
+                    unset($requestedProperties[$propRead]);
+                    $returnedProperties[200][$propRead] = new DAV\Property\HrefList($readList);
+                }
+                if (in_array($propWrite,$requestedProperties)) {
+                    unset($requestedProperties[$propWrite]);
+                    $returnedProperties[200][$propWrite] = new DAV\Property\HrefList($writeList);
+                }
+
+            }
+
+            // notification-URL property
+            $notificationUrl = '{' . self::NS_CALENDARSERVER . '}notification-URL';
+            if (($index = array_search($notificationUrl, $requestedProperties)) !== false) {
+                $principalId = $node->getName();
+                $calendarHomePath = 'calendars/' . $principalId . '/notifications/';
+                unset($requestedProperties[$index]);
+                $returnedProperties[200][$notificationUrl] = new DAV\Property\Href($calendarHomePath);
+            }
+
+        } // instanceof IPrincipal
+
+        if ($node instanceof Notifications\INode) {
+
+            $propertyName = '{' . self::NS_CALENDARSERVER . '}notificationtype';
+            if (($index = array_search($propertyName, $requestedProperties)) !== false) {
+
+                $returnedProperties[200][$propertyName] =
+                    $node->getNotificationType();
+
+                unset($requestedProperties[$index]);
+
+            }
+
+        } // instanceof Notifications_INode
+
+
+        if ($node instanceof ICalendarObject) {
+            // The calendar-data property is not supposed to be a 'real'
+            // property, but in large chunks of the spec it does act as such.
+            // Therefore we simply expose it as a property.
+            $calDataProp = '{' . Plugin::NS_CALDAV . '}calendar-data';
+            if (in_array($calDataProp, $requestedProperties)) {
+                unset($requestedProperties[$calDataProp]);
+                $val = $node->get();
+                if (is_resource($val))
+                    $val = stream_get_contents($val);
+
+                // Taking out \r to not screw up the xml output
+                $returnedProperties[200][$calDataProp] = str_replace("\r","", $val);
+
+            }
+        }
+
+    }
+
+    /**
+     * This function handles the calendar-multiget REPORT.
+     *
+     * This report is used by the client to fetch the content of a series
+     * of urls. Effectively avoiding a lot of redundant requests.
+     *
+     * @param \DOMNode $dom
+     * @return void
+     */
+    public function calendarMultiGetReport($dom) {
+
+        $properties = array_keys(DAV\XMLUtil::parseProperties($dom->firstChild));
+        $hrefElems = $dom->getElementsByTagNameNS('urn:DAV','href');
+
+        $xpath = new \DOMXPath($dom);
+        $xpath->registerNameSpace('cal',Plugin::NS_CALDAV);
+        $xpath->registerNameSpace('dav','urn:DAV');
+
+        $expand = $xpath->query('/cal:calendar-multiget/dav:prop/cal:calendar-data/cal:expand');
+        if ($expand->length>0) {
+            $expandElem = $expand->item(0);
+            $start = $expandElem->getAttribute('start');
+            $end = $expandElem->getAttribute('end');
+            if(!$start || !$end) {
+                throw new DAV\Exception\BadRequest('The "start" and "end" attributes are required for the CALDAV:expand element');
+            }
+            $start = VObject\DateTimeParser::parseDateTime($start);
+            $end = VObject\DateTimeParser::parseDateTime($end);
+
+            if ($end <= $start) {
+                throw new DAV\Exception\BadRequest('The end-date must be larger than the start-date in the expand element.');
+            }
+
+            $expand = true;
+
+        } else {
+
+            $expand = false;
+
+        }
+
+        foreach($hrefElems as $elem) {
+            $uri = $this->server->calculateUri($elem->nodeValue);
+            list($objProps) = $this->server->getPropertiesForPath($uri,$properties);
+
+            if ($expand && isset($objProps[200]['{' . self::NS_CALDAV . '}calendar-data'])) {
+                $vObject = VObject\Reader::read($objProps[200]['{' . self::NS_CALDAV . '}calendar-data']);
+                $vObject->expand($start, $end);
+                $objProps[200]['{' . self::NS_CALDAV . '}calendar-data'] = $vObject->serialize();
+            }
+
+            $propertyList[]=$objProps;
+
+        }
+
+        $prefer = $this->server->getHTTPPRefer();
+
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Vary','Brief,Prefer');
+        $this->server->httpResponse->sendBody($this->server->generateMultiStatus($propertyList, $prefer['return-minimal']));
+
+    }
+
+    /**
+     * This function handles the calendar-query REPORT
+     *
+     * This report is used by clients to request calendar objects based on
+     * complex conditions.
+     *
+     * @param \DOMNode $dom
+     * @return void
+     */
+    public function calendarQueryReport($dom) {
+
+        $parser = new CalendarQueryParser($dom);
+        $parser->parse();
+
+        $node = $this->server->tree->getNodeForPath($this->server->getRequestUri());
+        $depth = $this->server->getHTTPDepth(0);
+
+        // The default result is an empty array
+        $result = array();
+
+        // The calendarobject was requested directly. In this case we handle
+        // this locally.
+        if ($depth == 0 && $node instanceof ICalendarObject) {
+
+            $requestedCalendarData = true;
+            $requestedProperties = $parser->requestedProperties;
+
+            if (!in_array('{urn:ietf:params:xml:ns:caldav}calendar-data', $requestedProperties)) {
+
+                // We always retrieve calendar-data, as we need it for filtering.
+                $requestedProperties[] = '{urn:ietf:params:xml:ns:caldav}calendar-data';
+
+                // If calendar-data wasn't explicitly requested, we need to remove
+                // it after processing.
+                $requestedCalendarData = false;
+            }
+
+            $properties = $this->server->getPropertiesForPath(
+                $this->server->getRequestUri(),
+                $requestedProperties,
+                0
+            );
+
+            // This array should have only 1 element, the first calendar
+            // object.
+            $properties = current($properties);
+
+            // If there wasn't any calendar-data returned somehow, we ignore
+            // this.
+            if (isset($properties[200]['{urn:ietf:params:xml:ns:caldav}calendar-data'])) {
+
+                $validator = new CalendarQueryValidator();
+
+                $vObject = VObject\Reader::read($properties[200]['{urn:ietf:params:xml:ns:caldav}calendar-data']);
+                if ($validator->validate($vObject,$parser->filters)) {
+
+                    // If the client didn't require the calendar-data property,
+                    // we won't give it back.
+                    if (!$requestedCalendarData) {
+                        unset($properties[200]['{urn:ietf:params:xml:ns:caldav}calendar-data']);
+                    } else {
+                        if ($parser->expand) {
+                            $vObject->expand($parser->expand['start'], $parser->expand['end']);
+                            $properties[200]['{' . self::NS_CALDAV . '}calendar-data'] = $vObject->serialize();
+                        }
+                    }
+
+                    $result = array($properties);
+
+                }
+
+            }
+
+        }
+        // If we're dealing with a calendar, the calendar itself is responsible
+        // for the calendar-query.
+        if ($node instanceof ICalendar && $depth = 1) {
+
+            $nodePaths = $node->calendarQuery($parser->filters);
+
+            foreach($nodePaths as $path) {
+
+                list($properties) =
+                    $this->server->getPropertiesForPath($this->server->getRequestUri() . '/' . $path, $parser->requestedProperties);
+
+                if ($parser->expand) {
+                    // We need to do some post-processing
+                    $vObject = VObject\Reader::read($properties[200]['{urn:ietf:params:xml:ns:caldav}calendar-data']);
+                    $vObject->expand($parser->expand['start'], $parser->expand['end']);
+                    $properties[200]['{' . self::NS_CALDAV . '}calendar-data'] = $vObject->serialize();
+                }
+
+                $result[] = $properties;
+
+            }
+
+        }
+
+        $prefer = $this->server->getHTTPPRefer();
+
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Vary','Brief,Prefer');
+        $this->server->httpResponse->sendBody($this->server->generateMultiStatus($result, $prefer['return-minimal']));
+
+    }
+
+    /**
+     * This method is responsible for parsing the request and generating the
+     * response for the CALDAV:free-busy-query REPORT.
+     *
+     * @param \DOMNode $dom
+     * @return void
+     */
+    protected function freeBusyQueryReport(\DOMNode $dom) {
+
+        $start = null;
+        $end = null;
+
+        foreach($dom->firstChild->childNodes as $childNode) {
+
+            $clark = DAV\XMLUtil::toClarkNotation($childNode);
+            if ($clark == '{' . self::NS_CALDAV . '}time-range') {
+                $start = $childNode->getAttribute('start');
+                $end = $childNode->getAttribute('end');
+                break;
+            }
+
+        }
+        if ($start) {
+            $start = VObject\DateTimeParser::parseDateTime($start);
+        }
+        if ($end) {
+            $end = VObject\DateTimeParser::parseDateTime($end);
+        }
+
+        if (!$start && !$end) {
+            throw new DAV\Exception\BadRequest('The freebusy report must have a time-range filter');
+        }
+        $acl = $this->server->getPlugin('acl');
+
+        if (!$acl) {
+            throw new DAV\Exception('The ACL plugin must be loaded for free-busy queries to work');
+        }
+        $uri = $this->server->getRequestUri();
+        $acl->checkPrivileges($uri,'{' . self::NS_CALDAV . '}read-free-busy');
+
+        $calendar = $this->server->tree->getNodeForPath($uri);
+        if (!$calendar instanceof ICalendar) {
+            throw new DAV\Exception\NotImplemented('The free-busy-query REPORT is only implemented on calendars');
+        }
+
+        // Doing a calendar-query first, to make sure we get the most
+        // performance.
+        $urls = $calendar->calendarQuery(array(
+            'name' => 'VCALENDAR',
+            'comp-filters' => array(
+                array(
+                    'name' => 'VEVENT',
+                    'comp-filters' => array(),
+                    'prop-filters' => array(),
+                    'is-not-defined' => false,
+                    'time-range' => array(
+                        'start' => $start,
+                        'end' => $end,
+                    ),
+                ),
+            ),
+            'prop-filters' => array(),
+            'is-not-defined' => false,
+            'time-range' => null,
+        ));
+
+        $objects = array_map(function($url) use ($calendar) {
+            $obj = $calendar->getChild($url)->get();
+            return $obj;
+        }, $urls);
+
+        $generator = new VObject\FreeBusyGenerator();
+        $generator->setObjects($objects);
+        $generator->setTimeRange($start, $end);
+        $result = $generator->getResult();
+        $result = $result->serialize();
+
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->setHeader('Content-Type', 'text/calendar');
+        $this->server->httpResponse->setHeader('Content-Length', strlen($result));
+        $this->server->httpResponse->sendBody($result);
+
+    }
+
+    /**
+     * This method is triggered before a file gets updated with new content.
+     *
+     * This plugin uses this method to ensure that CalDAV objects receive
+     * valid calendar data.
+     *
+     * @param string $path
+     * @param DAV\IFile $node
+     * @param resource $data
+     * @return void
+     */
+    public function beforeWriteContent($path, DAV\IFile $node, &$data) {
+
+        if (!$node instanceof ICalendarObject)
+            return;
+
+        $this->validateICalendar($data, $path);
+
+    }
+
+    /**
+     * This method is triggered before a new file is created.
+     *
+     * This plugin uses this method to ensure that newly created calendar
+     * objects contain valid calendar data.
+     *
+     * @param string $path
+     * @param resource $data
+     * @param DAV\ICollection $parentNode
+     * @return void
+     */
+    public function beforeCreateFile($path, &$data, DAV\ICollection $parentNode) {
+
+        if (!$parentNode instanceof Calendar)
+            return;
+
+        $this->validateICalendar($data, $path);
+
+    }
+
+    /**
+     * This event is triggered before any HTTP request is handled.
+     *
+     * We use this to intercept GET calls to notification nodes, and return the
+     * proper response.
+     *
+     * @param string $method
+     * @param string $path
+     * @return void
+     */
+    public function beforeMethod($method, $path) {
+
+        if ($method!=='GET') return;
+
+        try {
+            $node = $this->server->tree->getNodeForPath($path);
+        } catch (DAV\Exception\NotFound $e) {
+            return;
+        }
+
+        if (!$node instanceof Notifications\INode)
+            return;
+
+        if (!$this->server->checkPreconditions(true)) return false;
+        $dom = new \DOMDocument('1.0', 'UTF-8');
+
+        $dom->formatOutput = true;
+
+        $root = $dom->createElement('cs:notification');
+        foreach($this->server->xmlNamespaces as $namespace => $prefix) {
+            $root->setAttribute('xmlns:' . $prefix, $namespace);
+        }
+
+        $dom->appendChild($root);
+        $node->getNotificationType()->serializeBody($this->server, $root);
+
+        $this->server->httpResponse->setHeader('Content-Type','application/xml');
+        $this->server->httpResponse->setHeader('ETag',$node->getETag());
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->sendBody($dom->saveXML());
+
+        return false;
+
+    }
+
+    /**
+     * Checks if the submitted iCalendar data is in fact, valid.
+     *
+     * An exception is thrown if it's not.
+     *
+     * @param resource|string $data
+     * @param string $path
+     * @return void
+     */
+    protected function validateICalendar(&$data, $path) {
+
+        // If it's a stream, we convert it to a string first.
+        if (is_resource($data)) {
+            $data = stream_get_contents($data);
+        }
+
+        // Converting the data to unicode, if needed.
+        $data = DAV\StringUtil::ensureUTF8($data);
+
+        try {
+
+            $vobj = VObject\Reader::read($data);
+
+        } catch (VObject\ParseException $e) {
+
+            throw new DAV\Exception\UnsupportedMediaType('This resource only supports valid iCalendar 2.0 data. Parse error: ' . $e->getMessage());
+
+        }
+
+        if ($vobj->name !== 'VCALENDAR') {
+            throw new DAV\Exception\UnsupportedMediaType('This collection can only support iCalendar objects.');
+        }
+
+        // Get the Supported Components for the target calendar
+        list($parentPath,$object) = DAV\URLUtil::splitPath($path);
+        $calendarProperties = $this->server->getProperties($parentPath,array('{urn:ietf:params:xml:ns:caldav}supported-calendar-component-set'));
+        $supportedComponents = $calendarProperties['{urn:ietf:params:xml:ns:caldav}supported-calendar-component-set']->getValue();
+
+        $foundType = null;
+        $foundUID = null;
+        foreach($vobj->getComponents() as $component) {
+            switch($component->name) {
+                case 'VTIMEZONE' :
+                    continue 2;
+                case 'VEVENT' :
+                case 'VTODO' :
+                case 'VJOURNAL' :
+                    if (is_null($foundType)) {
+                        $foundType = $component->name;
+                        if (!in_array($foundType, $supportedComponents)) {
+                            throw new Exception\InvalidComponentType('This calendar only supports ' . implode(', ', $supportedComponents) . '. We found a ' . $foundType);
+                        }
+                        if (!isset($component->UID)) {
+                            throw new DAV\Exception\BadRequest('Every ' . $component->name . ' component must have an UID');
+                        }
+                        $foundUID = (string)$component->UID;
+                    } else {
+                        if ($foundType !== $component->name) {
+                            throw new DAV\Exception\BadRequest('A calendar object must only contain 1 component. We found a ' . $component->name . ' as well as a ' . $foundType);
+                        }
+                        if ($foundUID !== (string)$component->UID) {
+                            throw new DAV\Exception\BadRequest('Every ' . $component->name . ' in this object must have identical UIDs');
+                        }
+                    }
+                    break;
+                default :
+                    throw new DAV\Exception\BadRequest('You are not allowed to create components of type: ' . $component->name . ' here');
+
+            }
+        }
+        if (!$foundType)
+            throw new DAV\Exception\BadRequest('iCalendar object must contain at least 1 of VEVENT, VTODO or VJOURNAL');
+
+    }
+
+    /**
+     * This method handles POST requests to the schedule-outbox.
+     *
+     * Currently, two types of requests are support:
+     *   * FREEBUSY requests from RFC 6638
+     *   * Simple iTIP messages from draft-desruisseaux-caldav-sched-04
+     *
+     * The latter is from an expired early draft of the CalDAV scheduling
+     * extensions, but iCal depends on a feature from that spec, so we
+     * implement it.
+     *
+     * @param Schedule\IOutbox $outboxNode
+     * @param string $outboxUri
+     * @return void
+     */
+    public function outboxRequest(Schedule\IOutbox $outboxNode, $outboxUri) {
+
+        // Parsing the request body
+        try {
+            $vObject = VObject\Reader::read($this->server->httpRequest->getBody(true));
+        } catch (VObject\ParseException $e) {
+            throw new DAV\Exception\BadRequest('The request body must be a valid iCalendar object. Parse error: ' . $e->getMessage());
+        }
+
+        // The incoming iCalendar object must have a METHOD property, and a
+        // component. The combination of both determines what type of request
+        // this is.
+        $componentType = null;
+        foreach($vObject->getComponents() as $component) {
+            if ($component->name !== 'VTIMEZONE') {
+                $componentType = $component->name;
+                break;
+            }
+        }
+        if (is_null($componentType)) {
+            throw new DAV\Exception\BadRequest('We expected at least one VTODO, VJOURNAL, VFREEBUSY or VEVENT component');
+        }
+
+        // Validating the METHOD
+        $method = strtoupper((string)$vObject->METHOD);
+        if (!$method) {
+            throw new DAV\Exception\BadRequest('A METHOD property must be specified in iTIP messages');
+        }
+
+        // So we support two types of requests:
+        //
+        // REQUEST with a VFREEBUSY component
+        // REQUEST, REPLY, ADD, CANCEL on VEVENT components
+
+        $acl = $this->server->getPlugin('acl');
+
+        if ($componentType === 'VFREEBUSY' && $method === 'REQUEST') {
+
+            $acl && $acl->checkPrivileges($outboxUri,'{' . Plugin::NS_CALDAV . '}schedule-query-freebusy');
+            $this->handleFreeBusyRequest($outboxNode, $vObject);
+
+        } elseif ($componentType === 'VEVENT' && in_array($method, array('REQUEST','REPLY','ADD','CANCEL'))) {
+
+            $acl && $acl->checkPrivileges($outboxUri,'{' . Plugin::NS_CALDAV . '}schedule-post-vevent');
+            $this->handleEventNotification($outboxNode, $vObject);
+
+        } else {
+
+            throw new DAV\Exception\NotImplemented('SabreDAV supports only VFREEBUSY (REQUEST) and VEVENT (REQUEST, REPLY, ADD, CANCEL)');
+
+        }
+
+    }
+
+    /**
+     * This method handles the REQUEST, REPLY, ADD and CANCEL methods for
+     * VEVENT iTip messages.
+     *
+     * @return void
+     */
+    protected function handleEventNotification(Schedule\IOutbox $outboxNode, VObject\Component $vObject) {
+
+        $originator = $this->server->httpRequest->getHeader('Originator');
+        $recipients = $this->server->httpRequest->getHeader('Recipient');
+
+        if (!$originator) {
+            throw new DAV\Exception\BadRequest('The Originator: header must be specified when making POST requests');
+        }
+        if (!$recipients) {
+            throw new DAV\Exception\BadRequest('The Recipient: header must be specified when making POST requests');
+        }
+
+        $recipients = explode(',',$recipients);
+        foreach($recipients as $k=>$recipient) {
+
+            $recipient = trim($recipient);
+            if (!preg_match('/^mailto:(.*)@(.*)$/i', $recipient)) {
+                throw new DAV\Exception\BadRequest('Recipients must start with mailto: and must be valid email address');
+            }
+            $recipient = substr($recipient, 7);
+            $recipients[$k] = $recipient;
+        }
+
+        // We need to make sure that 'originator' matches one of the email
+        // addresses of the selected principal.
+        $principal = $outboxNode->getOwner();
+        $props = $this->server->getProperties($principal,array(
+            '{' . self::NS_CALDAV . '}calendar-user-address-set',
+        ));
+
+        $addresses = array();
+        if (isset($props['{' . self::NS_CALDAV . '}calendar-user-address-set'])) {
+            $addresses = $props['{' . self::NS_CALDAV . '}calendar-user-address-set']->getHrefs();
+        }
+
+        $found = false;
+        foreach($addresses as $address) {
+
+            // Trimming the / on both sides, just in case..
+            if (rtrim(strtolower($originator),'/') === rtrim(strtolower($address),'/')) {
+                $found = true;
+                break;
+            }
+
+        }
+
+        if (!$found) {
+            throw new DAV\Exception\Forbidden('The addresses specified in the Originator header did not match any addresses in the owners calendar-user-address-set header');
+        }
+
+        // If the Originator header was a url, and not a mailto: address..
+        // we're going to try to pull the mailto: from the vobject body.
+        if (strtolower(substr($originator,0,7)) !== 'mailto:') {
+            $originator = (string)$vObject->VEVENT->ORGANIZER;
+
+        }
+        if (strtolower(substr($originator,0,7)) !== 'mailto:') {
+            throw new DAV\Exception\Forbidden('Could not find mailto: address in both the Orignator header, and the ORGANIZER property in the VEVENT');
+        }
+        $originator = substr($originator,7);
+
+        $result = $this->iMIPMessage($originator, $recipients, $vObject, $principal);
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml');
+        $this->server->httpResponse->sendBody($this->generateScheduleResponse($result));
+
+    }
+
+    /**
+     * Sends an iMIP message by email.
+     *
+     * This method must return an array with status codes per recipient.
+     * This should look something like:
+     *
+     * array(
+     *    'user1@example.org' => '2.0;Success'
+     * )
+     *
+     * Formatting for this status code can be found at:
+     * https://tools.ietf.org/html/rfc5545#section-3.8.8.3
+     *
+     * A list of valid status codes can be found at:
+     * https://tools.ietf.org/html/rfc5546#section-3.6
+     *
+     * @param string $originator
+     * @param array $recipients
+     * @param VObject\Component $vObject
+     * @param string $principal Principal url
+     * @return array 
+     */
+    protected function iMIPMessage($originator, array $recipients, VObject\Component $vObject, $principal) {
+
+        if (!$this->imipHandler) {
+            $resultStatus = '5.2;This server does not support this operation';
+        } else {
+            $this->imipHandler->sendMessage($originator, $recipients, $vObject, $principal);
+            $resultStatus = '2.0;Success';
+        }
+
+        $result = array();
+        foreach($recipients as $recipient) {
+            $result[$recipient] = $resultStatus;
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Generates a schedule-response XML body
+     *
+     * The recipients array is a key->value list, containing email addresses
+     * and iTip status codes. See the iMIPMessage method for a description of
+     * the value.
+     *
+     * @param array $recipients
+     * @return string
+     */
+    public function generateScheduleResponse(array $recipients) {
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        $dom->formatOutput = true;
+        $xscheduleResponse = $dom->createElement('cal:schedule-response');
+        $dom->appendChild($xscheduleResponse);
+
+        foreach($this->server->xmlNamespaces as $namespace=>$prefix) {
+
+            $xscheduleResponse->setAttribute('xmlns:' . $prefix, $namespace);
+
+        }
+
+        foreach($recipients as $recipient=>$status) {
+            $xresponse = $dom->createElement('cal:response');
+
+            $xrecipient = $dom->createElement('cal:recipient');
+            $xrecipient->appendChild($dom->createTextNode($recipient));
+            $xresponse->appendChild($xrecipient);
+
+            $xrequestStatus = $dom->createElement('cal:request-status');
+            $xrequestStatus->appendChild($dom->createTextNode($status));
+            $xresponse->appendChild($xrequestStatus);
+
+            $xscheduleResponse->appendChild($xresponse);
+
+        }
+
+        return $dom->saveXML();
+
+    }
+
+    /**
+     * This method is responsible for parsing a free-busy query request and
+     * returning it's result.
+     *
+     * @param Schedule\IOutbox $outbox
+     * @param string $request
+     * @return string
+     */
+    protected function handleFreeBusyRequest(Schedule\IOutbox $outbox, VObject\Component $vObject) {
+
+        $vFreeBusy = $vObject->VFREEBUSY;
+        $organizer = $vFreeBusy->organizer;
+
+        $organizer = (string)$organizer;
+
+        // Validating if the organizer matches the owner of the inbox.
+        $owner = $outbox->getOwner();
+
+        $caldavNS = '{' . Plugin::NS_CALDAV . '}';
+
+        $uas = $caldavNS . 'calendar-user-address-set';
+        $props = $this->server->getProperties($owner,array($uas));
+
+        if (empty($props[$uas]) || !in_array($organizer, $props[$uas]->getHrefs())) {
+            throw new DAV\Exception\Forbidden('The organizer in the request did not match any of the addresses for the owner of this inbox');
+        }
+
+        if (!isset($vFreeBusy->ATTENDEE)) {
+            throw new DAV\Exception\BadRequest('You must at least specify 1 attendee');
+        }
+
+        $attendees = array();
+        foreach($vFreeBusy->ATTENDEE as $attendee) {
+            $attendees[]= (string)$attendee;
+        }
+
+
+        if (!isset($vFreeBusy->DTSTART) || !isset($vFreeBusy->DTEND)) {
+            throw new DAV\Exception\BadRequest('DTSTART and DTEND must both be specified');
+        }
+
+        $startRange = $vFreeBusy->DTSTART->getDateTime();
+        $endRange = $vFreeBusy->DTEND->getDateTime();
+
+        $results = array();
+        foreach($attendees as $attendee) {
+            $results[] = $this->getFreeBusyForEmail($attendee, $startRange, $endRange, $vObject);
+        }
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        $dom->formatOutput = true;
+        $scheduleResponse = $dom->createElement('cal:schedule-response');
+        foreach($this->server->xmlNamespaces as $namespace=>$prefix) {
+
+            $scheduleResponse->setAttribute('xmlns:' . $prefix,$namespace);
+
+        }
+        $dom->appendChild($scheduleResponse);
+
+        foreach($results as $result) {
+            $response = $dom->createElement('cal:response');
+
+            $recipient = $dom->createElement('cal:recipient');
+            $recipientHref = $dom->createElement('d:href');
+
+            $recipientHref->appendChild($dom->createTextNode($result['href']));
+            $recipient->appendChild($recipientHref);
+            $response->appendChild($recipient);
+
+            $reqStatus = $dom->createElement('cal:request-status');
+            $reqStatus->appendChild($dom->createTextNode($result['request-status']));
+            $response->appendChild($reqStatus);
+
+            if (isset($result['calendar-data'])) {
+
+                $calendardata = $dom->createElement('cal:calendar-data');
+                $calendardata->appendChild($dom->createTextNode(str_replace("\r\n","\n",$result['calendar-data']->serialize())));
+                $response->appendChild($calendardata);
+
+            }
+            $scheduleResponse->appendChild($response);
+        }
+
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml');
+        $this->server->httpResponse->sendBody($dom->saveXML());
+
+    }
+
+    /**
+     * Returns free-busy information for a specific address. The returned
+     * data is an array containing the following properties:
+     *
+     * calendar-data : A VFREEBUSY VObject
+     * request-status : an iTip status code.
+     * href: The principal's email address, as requested
+     *
+     * The following request status codes may be returned:
+     *   * 2.0;description
+     *   * 3.7;description
+     *
+     * @param string $email address
+     * @param \DateTime $start
+     * @param \DateTime $end
+     * @param VObject\Component $request
+     * @return array
+     */
+    protected function getFreeBusyForEmail($email, \DateTime $start, \DateTime $end, VObject\Component $request) {
+
+        $caldavNS = '{' . Plugin::NS_CALDAV . '}';
+
+        $aclPlugin = $this->server->getPlugin('acl');
+        if (substr($email,0,7)==='mailto:') $email = substr($email,7);
+
+        $result = $aclPlugin->principalSearch(
+            array('{http://sabredav.org/ns}email-address' => $email),
+            array(
+                '{DAV:}principal-URL', $caldavNS . 'calendar-home-set',
+                '{http://sabredav.org/ns}email-address',
+            )
+        );
+
+        if (!count($result)) {
+            return array(
+                'request-status' => '3.7;Could not find principal',
+                'href' => 'mailto:' . $email,
+            );
+        }
+
+        if (!isset($result[0][200][$caldavNS . 'calendar-home-set'])) {
+            return array(
+                'request-status' => '3.7;No calendar-home-set property found',
+                'href' => 'mailto:' . $email,
+            );
+        }
+        $homeSet = $result[0][200][$caldavNS . 'calendar-home-set']->getHref();
+
+        // Grabbing the calendar list
+        $objects = array();
+        foreach($this->server->tree->getNodeForPath($homeSet)->getChildren() as $node) {
+            if (!$node instanceof ICalendar) {
+                continue;
+            }
+            $aclPlugin->checkPrivileges($homeSet . $node->getName() ,$caldavNS . 'read-free-busy');
+
+            // Getting the list of object uris within the time-range
+            $urls = $node->calendarQuery(array(
+                'name' => 'VCALENDAR',
+                'comp-filters' => array(
+                    array(
+                        'name' => 'VEVENT',
+                        'comp-filters' => array(),
+                        'prop-filters' => array(),
+                        'is-not-defined' => false,
+                        'time-range' => array(
+                            'start' => $start,
+                            'end' => $end,
+                        ),
+                    ),
+                ),
+                'prop-filters' => array(),
+                'is-not-defined' => false,
+                'time-range' => null,
+            ));
+
+            $calObjects = array_map(function($url) use ($node) {
+                $obj = $node->getChild($url)->get();
+                return $obj;
+            }, $urls);
+
+            $objects = array_merge($objects,$calObjects);
+
+        }
+
+        $vcalendar = new VObject\Component\VCalendar();
+        $vcalendar->VERSION = '2.0';
+        $vcalendar->METHOD = 'REPLY';
+        $vcalendar->CALSCALE = 'GREGORIAN';
+        $vcalendar->PRODID = '-//SabreDAV//SabreDAV ' . DAV\Version::VERSION . '//EN';
+
+        $generator = new VObject\FreeBusyGenerator();
+        $generator->setObjects($objects);
+        $generator->setTimeRange($start, $end);
+        $generator->setBaseObject($vcalendar);
+
+        $result = $generator->getResult();
+
+        $vcalendar->VFREEBUSY->ATTENDEE = 'mailto:' . $email;
+        $vcalendar->VFREEBUSY->UID = (string)$request->VFREEBUSY->UID;
+        $vcalendar->VFREEBUSY->ORGANIZER = clone $request->VFREEBUSY->ORGANIZER;
+
+        return array(
+            'calendar-data' => $result,
+            'request-status' => '2.0;Success',
+            'href' => 'mailto:' . $email,
+        );
+    }
+
+    /**
+     * This method is used to generate HTML output for the
+     * DAV\Browser\Plugin. This allows us to generate an interface users
+     * can use to create new calendars.
+     *
+     * @param DAV\INode $node
+     * @param string $output
+     * @return bool
+     */
+    public function htmlActionsPanel(DAV\INode $node, &$output) {
+
+        if (!$node instanceof UserCalendars)
+            return;
+
+        $output.= '<tr><td colspan="2"><form method="post" action="">
+            <h3>Create new calendar</h3>
+            <input type="hidden" name="sabreAction" value="mkcalendar" />
+            <label>Name (uri):</label> <input type="text" name="name" /><br />
+            <label>Display name:</label> <input type="text" name="{DAV:}displayname" /><br />
+            <input type="submit" value="create" />
+            </form>
+            </td></tr>';
+
+        return false;
+
+    }
+
+    /**
+     * This method allows us to intercept the 'mkcalendar' sabreAction. This
+     * action enables the user to create new calendars from the browser plugin.
+     *
+     * @param string $uri
+     * @param string $action
+     * @param array $postVars
+     * @return bool
+     */
+    public function browserPostAction($uri, $action, array $postVars) {
+
+        if ($action!=='mkcalendar')
+            return;
+
+        $resourceType = array('{DAV:}collection','{urn:ietf:params:xml:ns:caldav}calendar');
+        $properties = array();
+        if (isset($postVars['{DAV:}displayname'])) {
+            $properties['{DAV:}displayname'] = $postVars['{DAV:}displayname'];
+        }
+        $this->server->createCollection($uri . '/' . $postVars['name'],$resourceType,$properties);
+        return false;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/Collection.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/Collection.php
new file mode 100644
index 0000000..e78fc9f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/Collection.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+use OldSabre\DAVACL;
+
+/**
+ * Principal collection
+ *
+ * This is an alternative collection to the standard ACL principal collection.
+ * This collection adds support for the calendar-proxy-read and
+ * calendar-proxy-write sub-principals, as defined by the caldav-proxy
+ * specification.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Collection extends DAVACL\AbstractPrincipalCollection {
+
+    /**
+     * Returns a child object based on principal information
+     *
+     * @param array $principalInfo
+     * @return User
+     */
+    public function getChildForPrincipal(array $principalInfo) {
+
+        return new User($this->principalBackend, $principalInfo);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyRead.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyRead.php
new file mode 100644
index 0000000..5194c0b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyRead.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+
+use OldSabre\DAVACL;
+
+/**
+ * ProxyRead principal interface
+ *
+ * Any principal node implementing this interface will be picked up as a 'proxy
+ * principal group'.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IProxyRead extends DAVACL\IPrincipal {
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyWrite.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyWrite.php
new file mode 100644
index 0000000..d6b052e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/IProxyWrite.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+
+use OldSabre\DAVACL;
+
+/**
+ * ProxyWrite principal interface
+ *
+ * Any principal node implementing this interface will be picked up as a 'proxy
+ * principal group'.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IProxyWrite extends DAVACL\IPrincipal {
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyRead.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyRead.php
new file mode 100644
index 0000000..109f802
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyRead.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+use OldSabre\DAVACL;
+use OldSabre\DAV;
+
+/**
+ * ProxyRead principal
+ *
+ * This class represents a principal group, hosted under the main principal.
+ * This is needed to implement 'Calendar delegation' support. This class is
+ * instantiated by User.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ProxyRead implements IProxyRead {
+
+    /**
+     * Principal information from the parent principal.
+     *
+     * @var array
+     */
+    protected $principalInfo;
+
+    /**
+     * Principal backend
+     *
+     * @var DAVACL\PrincipalBackend\BackendInterface
+     */
+    protected $principalBackend;
+
+    /**
+     * Creates the object.
+     *
+     * Note that you MUST supply the parent principal information.
+     *
+     * @param DAVACL\PrincipalBackend\BackendInterface $principalBackend
+     * @param array $principalInfo
+     */
+    public function __construct(DAVACL\PrincipalBackend\BackendInterface $principalBackend, array $principalInfo) {
+
+        $this->principalInfo = $principalInfo;
+        $this->principalBackend = $principalBackend;
+
+    }
+
+    /**
+     * Returns this principals name.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return 'calendar-proxy-read';
+
+    }
+
+    /**
+     * Returns the last modification time
+     *
+     * @return null
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Deletes the current node
+     *
+     * @throws DAV\Exception\Forbidden
+     * @return void
+     */
+    public function delete() {
+
+        throw new DAV\Exception\Forbidden('Permission denied to delete node');
+
+    }
+
+    /**
+     * Renames the node
+     *
+     * @throws DAV\Exception\Forbidden
+     * @param string $name The new name
+     * @return void
+     */
+    public function setName($name) {
+
+        throw new DAV\Exception\Forbidden('Permission denied to rename file');
+
+    }
+
+
+    /**
+     * Returns a list of alternative urls for a principal
+     *
+     * This can for example be an email address, or ldap url.
+     *
+     * @return array
+     */
+    public function getAlternateUriSet() {
+
+        return array();
+
+    }
+
+    /**
+     * Returns the full principal url
+     *
+     * @return string
+     */
+    public function getPrincipalUrl() {
+
+        return $this->principalInfo['uri'] . '/' . $this->getName();
+
+    }
+
+    /**
+     * Returns the list of group members
+     *
+     * If this principal is a group, this function should return
+     * all member principal uri's for the group.
+     *
+     * @return array
+     */
+    public function getGroupMemberSet() {
+
+        return $this->principalBackend->getGroupMemberSet($this->getPrincipalUrl());
+
+    }
+
+    /**
+     * Returns the list of groups this principal is member of
+     *
+     * If this principal is a member of a (list of) groups, this function
+     * should return a list of principal uri's for it's members.
+     *
+     * @return array
+     */
+    public function getGroupMembership() {
+
+        return $this->principalBackend->getGroupMembership($this->getPrincipalUrl());
+
+    }
+
+    /**
+     * Sets a list of group members
+     *
+     * If this principal is a group, this method sets all the group members.
+     * The list of members is always overwritten, never appended to.
+     *
+     * This method should throw an exception if the members could not be set.
+     *
+     * @param array $principals
+     * @return void
+     */
+    public function setGroupMemberSet(array $principals) {
+
+        $this->principalBackend->setGroupMemberSet($this->getPrincipalUrl(), $principals);
+
+    }
+
+    /**
+     * Returns the displayname
+     *
+     * This should be a human readable name for the principal.
+     * If none is available, return the nodename.
+     *
+     * @return string
+     */
+    public function getDisplayName() {
+
+        return $this->getName();
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyWrite.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyWrite.php
new file mode 100644
index 0000000..7295254
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/ProxyWrite.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+use OldSabre\DAVACL;
+use OldSabre\DAV;
+
+/**
+ * ProxyWrite principal
+ *
+ * This class represents a principal group, hosted under the main principal.
+ * This is needed to implement 'Calendar delegation' support. This class is
+ * instantiated by User.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ProxyWrite implements IProxyWrite {
+
+    /**
+     * Parent principal information
+     *
+     * @var array
+     */
+    protected $principalInfo;
+
+    /**
+     * Principal Backend
+     *
+     * @var DAVACL\PrincipalBackend\BackendInterface
+     */
+    protected $principalBackend;
+
+    /**
+     * Creates the object
+     *
+     * Note that you MUST supply the parent principal information.
+     *
+     * @param DAVACL\PrincipalBackend\BackendInterface $principalBackend
+     * @param array $principalInfo
+     */
+    public function __construct(DAVACL\PrincipalBackend\BackendInterface $principalBackend, array $principalInfo) {
+
+        $this->principalInfo = $principalInfo;
+        $this->principalBackend = $principalBackend;
+
+    }
+
+    /**
+     * Returns this principals name.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return 'calendar-proxy-write';
+
+    }
+
+    /**
+     * Returns the last modification time
+     *
+     * @return null
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Deletes the current node
+     *
+     * @throws DAV\Exception\Forbidden
+     * @return void
+     */
+    public function delete() {
+
+        throw new DAV\Exception\Forbidden('Permission denied to delete node');
+
+    }
+
+    /**
+     * Renames the node
+     *
+     * @throws DAV\Exception\Forbidden
+     * @param string $name The new name
+     * @return void
+     */
+    public function setName($name) {
+
+        throw new DAV\Exception\Forbidden('Permission denied to rename file');
+
+    }
+
+
+    /**
+     * Returns a list of alternative urls for a principal
+     *
+     * This can for example be an email address, or ldap url.
+     *
+     * @return array
+     */
+    public function getAlternateUriSet() {
+
+        return array();
+
+    }
+
+    /**
+     * Returns the full principal url
+     *
+     * @return string
+     */
+    public function getPrincipalUrl() {
+
+        return $this->principalInfo['uri'] . '/' . $this->getName();
+
+    }
+
+    /**
+     * Returns the list of group members
+     *
+     * If this principal is a group, this function should return
+     * all member principal uri's for the group.
+     *
+     * @return array
+     */
+    public function getGroupMemberSet() {
+
+        return $this->principalBackend->getGroupMemberSet($this->getPrincipalUrl());
+
+    }
+
+    /**
+     * Returns the list of groups this principal is member of
+     *
+     * If this principal is a member of a (list of) groups, this function
+     * should return a list of principal uri's for it's members.
+     *
+     * @return array
+     */
+    public function getGroupMembership() {
+
+        return $this->principalBackend->getGroupMembership($this->getPrincipalUrl());
+
+    }
+
+    /**
+     * Sets a list of group members
+     *
+     * If this principal is a group, this method sets all the group members.
+     * The list of members is always overwritten, never appended to.
+     *
+     * This method should throw an exception if the members could not be set.
+     *
+     * @param array $principals
+     * @return void
+     */
+    public function setGroupMemberSet(array $principals) {
+
+        $this->principalBackend->setGroupMemberSet($this->getPrincipalUrl(), $principals);
+
+    }
+
+    /**
+     * Returns the displayname
+     *
+     * This should be a human readable name for the principal.
+     * If none is available, return the nodename.
+     *
+     * @return string
+     */
+    public function getDisplayName() {
+
+        return $this->getName();
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/User.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/User.php
new file mode 100644
index 0000000..345562a
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Principal/User.php
@@ -0,0 +1,134 @@
+<?php
+
+namespace OldSabre\CalDAV\Principal;
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * CalDAV principal
+ *
+ * This is a standard user-principal for CalDAV. This principal is also a
+ * collection and returns the caldav-proxy-read and caldav-proxy-write child
+ * principals.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class User extends DAVACL\Principal implements DAV\ICollection {
+
+    /**
+     * Creates a new file in the directory
+     *
+     * @param string $name Name of the file
+     * @param resource $data Initial payload, passed as a readable stream resource.
+     * @throws DAV\Exception\Forbidden
+     * @return void
+     */
+    public function createFile($name, $data = null) {
+
+        throw new DAV\Exception\Forbidden('Permission denied to create file (filename ' . $name . ')');
+
+    }
+
+    /**
+     * Creates a new subdirectory
+     *
+     * @param string $name
+     * @throws DAV\Exception\Forbidden
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        throw new DAV\Exception\Forbidden('Permission denied to create directory');
+
+    }
+
+    /**
+     * Returns a specific child node, referenced by its name
+     *
+     * @param string $name
+     * @return DAV\INode
+     */
+    public function getChild($name) {
+
+        $principal = $this->principalBackend->getPrincipalByPath($this->getPrincipalURL() . '/' . $name);
+        if (!$principal) {
+            throw new DAV\Exception\NotFound('Node with name ' . $name . ' was not found');
+        }
+        if ($name === 'calendar-proxy-read')
+            return new ProxyRead($this->principalBackend, $this->principalProperties);
+
+        if ($name === 'calendar-proxy-write')
+            return new ProxyWrite($this->principalBackend, $this->principalProperties);
+
+        throw new DAV\Exception\NotFound('Node with name ' . $name . ' was not found');
+
+    }
+
+    /**
+     * Returns an array with all the child nodes
+     *
+    * @return DAV\INode[]
+     */
+    public function getChildren() {
+
+        $r = array();
+        if ($this->principalBackend->getPrincipalByPath($this->getPrincipalURL() . '/calendar-proxy-read')) {
+            $r[] = new ProxyRead($this->principalBackend, $this->principalProperties);
+        }
+        if ($this->principalBackend->getPrincipalByPath($this->getPrincipalURL() . '/calendar-proxy-write')) {
+            $r[] = new ProxyWrite($this->principalBackend, $this->principalProperties);
+        }
+
+        return $r;
+
+    }
+
+    /**
+     * Returns whether or not the child node exists
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function childExists($name) {
+
+        try {
+            $this->getChild($name);
+            return true;
+        } catch (DAV\Exception\NotFound $e) {
+            return false;
+        }
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        $acl = parent::getACL();
+        $acl[] = array(
+            'privilege' => '{DAV:}read',
+            'principal' => $this->principalProperties['uri'] . '/calendar-proxy-read',
+            'protected' => true,
+        );
+        $acl[] = array(
+            'privilege' => '{DAV:}read',
+            'principal' => $this->principalProperties['uri'] . '/calendar-proxy-write',
+            'protected' => true,
+        );
+        return $acl;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/AllowedSharingModes.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/AllowedSharingModes.php
new file mode 100644
index 0000000..918c3d1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/AllowedSharingModes.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * AllowedSharingModes
+ *
+ * This property encodes the 'allowed-sharing-modes' property, as defined by
+ * the 'caldav-sharing-02' spec, in the http://calendarserver.org/ns/
+ * namespace.
+ *
+ * This property is a representation of the supported-calendar_component-set
+ * property in the CalDAV namespace. It simply requires an array of components,
+ * such as VEVENT, VTODO
+ *
+ * @see https://trac.calendarserver.org/browser/CalendarServer/trunk/doc/Extensions/caldav-sharing-02.txt
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AllowedSharingModes extends DAV\Property {
+
+    /**
+     * Whether or not a calendar can be shared with another user
+     *
+     * @var bool
+     */
+    protected $canBeShared;
+
+    /**
+     * Whether or not the calendar can be placed on a public url.
+     *
+     * @var bool
+     */
+    protected $canBePublished;
+
+    /**
+     * Constructor
+     *
+     * @param bool $canBeShared
+     * @param bool $canBePublished
+     * @return void
+     */
+    public function __construct($canBeShared, $canBePublished) {
+
+        $this->canBeShared = $canBeShared;
+        $this->canBePublished = $canBePublished;
+
+    }
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $node) {
+
+       $doc = $node->ownerDocument;
+       if ($this->canBeShared) {
+            $xcomp = $doc->createElement('cs:can-be-shared');
+            $node->appendChild($xcomp);
+       }
+       if ($this->canBePublished) {
+            $xcomp = $doc->createElement('cs:can-be-published');
+            $node->appendChild($xcomp);
+       }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/Invite.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/Invite.php
new file mode 100644
index 0000000..0e2f8f1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/Invite.php
@@ -0,0 +1,227 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+
+use OldSabre\CalDAV\SharingPlugin as SharingPlugin;
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * Invite property
+ *
+ * This property encodes the 'invite' property, as defined by
+ * the 'caldav-sharing-02' spec, in the http://calendarserver.org/ns/
+ * namespace.
+ *
+ * @see https://trac.calendarserver.org/browser/CalendarServer/trunk/doc/Extensions/caldav-sharing-02.txt
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Invite extends DAV\Property {
+
+    /**
+     * The list of users a calendar has been shared to.
+     *
+     * @var array
+     */
+    protected $users;
+
+    /**
+     * The organizer contains information about the person who shared the
+     * object.
+     *
+     * @var array
+     */
+    protected $organizer;
+
+    /**
+     * Creates the property.
+     *
+     * Users is an array. Each element of the array has the following
+     * properties:
+     *
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first and lastname for a user.
+     *   * status - One of the SharingPlugin::STATUS_* constants.
+     *   * readOnly - true or false
+     *   * summary - Optional, description of the share
+     *
+     * The organizer key is optional to specify. It's only useful when a
+     * 'sharee' requests the sharing information.
+     *
+     * The organizer may have the following properties:
+     *   * href - Often a mailto: address.
+     *   * commonName - Optional human-readable name.
+     *   * firstName - Optional first name.
+     *   * lastName - Optional last name.
+     *
+     * If you wonder why these two structures are so different, I guess a
+     * valid answer is that the current spec is still a draft.
+     *
+     * @param array $users
+     */
+    public function __construct(array $users, array $organizer = null) {
+
+        $this->users = $users;
+        $this->organizer = $organizer;
+
+    }
+
+    /**
+     * Returns the list of users, as it was passed to the constructor.
+     *
+     * @return array
+     */
+    public function getValue() {
+
+        return $this->users;
+
+    }
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+       $doc = $node->ownerDocument;
+
+       if (!is_null($this->organizer)) {
+
+           $xorganizer = $doc->createElement('cs:organizer');
+
+           $href = $doc->createElement('d:href');
+           $href->appendChild($doc->createTextNode($this->organizer['href']));
+           $xorganizer->appendChild($href);
+
+           if (isset($this->organizer['commonName']) && $this->organizer['commonName']) {
+               $commonName = $doc->createElement('cs:common-name');
+               $commonName->appendChild($doc->createTextNode($this->organizer['commonName']));
+               $xorganizer->appendChild($commonName);
+           }
+           if (isset($this->organizer['firstName']) && $this->organizer['firstName']) {
+               $firstName = $doc->createElement('cs:first-name');
+               $firstName->appendChild($doc->createTextNode($this->organizer['firstName']));
+               $xorganizer->appendChild($firstName);
+           }
+           if (isset($this->organizer['lastName']) && $this->organizer['lastName']) {
+               $lastName = $doc->createElement('cs:last-name');
+               $lastName->appendChild($doc->createTextNode($this->organizer['lastName']));
+               $xorganizer->appendChild($lastName);
+           }
+
+           $node->appendChild($xorganizer);
+
+
+       }
+
+       foreach($this->users as $user) {
+
+           $xuser = $doc->createElement('cs:user');
+
+           $href = $doc->createElement('d:href');
+           $href->appendChild($doc->createTextNode($user['href']));
+           $xuser->appendChild($href);
+
+           if (isset($user['commonName']) && $user['commonName']) {
+               $commonName = $doc->createElement('cs:common-name');
+               $commonName->appendChild($doc->createTextNode($user['commonName']));
+               $xuser->appendChild($commonName);
+           }
+
+           switch($user['status']) {
+
+               case SharingPlugin::STATUS_ACCEPTED :
+                   $status = $doc->createElement('cs:invite-accepted');
+                   $xuser->appendChild($status);
+                   break;
+               case SharingPlugin::STATUS_DECLINED :
+                   $status = $doc->createElement('cs:invite-declined');
+                   $xuser->appendChild($status);
+                   break;
+               case SharingPlugin::STATUS_NORESPONSE :
+                   $status = $doc->createElement('cs:invite-noresponse');
+                   $xuser->appendChild($status);
+                   break;
+               case SharingPlugin::STATUS_INVALID :
+                   $status = $doc->createElement('cs:invite-invalid');
+                   $xuser->appendChild($status);
+                   break;
+
+           }
+
+           $xaccess = $doc->createElement('cs:access');
+
+           if ($user['readOnly']) {
+                $xaccess->appendChild(
+                    $doc->createElement('cs:read')
+                );
+           } else {
+                $xaccess->appendChild(
+                    $doc->createElement('cs:read-write')
+                );
+           }
+           $xuser->appendChild($xaccess);
+
+           if (isset($user['summary']) && $user['summary']) {
+               $summary = $doc->createElement('cs:summary');
+               $summary->appendChild($doc->createTextNode($user['summary']));
+               $xuser->appendChild($summary);
+           }
+
+           $node->appendChild($xuser);
+
+       }
+
+
+    }
+
+    /**
+     * Unserializes the property.
+     *
+     * This static method should return a an instance of this object.
+     *
+     * @param \DOMElement $prop
+     * @return DAV\IProperty
+     */
+    static function unserialize(\DOMElement $prop) {
+
+        $xpath = new \DOMXPath($prop->ownerDocument);
+        $xpath->registerNamespace('cs', CalDAV\Plugin::NS_CALENDARSERVER);
+        $xpath->registerNamespace('d',  'urn:DAV');
+
+        $users = array();
+
+        foreach($xpath->query('cs:user', $prop) as $user) {
+
+            $status = null;
+            if ($xpath->evaluate('boolean(cs:invite-accepted)', $user)) {
+                $status = SharingPlugin::STATUS_ACCEPTED;
+            } elseif ($xpath->evaluate('boolean(cs:invite-declined)', $user)) {
+                $status = SharingPlugin::STATUS_DECLINED;
+            } elseif ($xpath->evaluate('boolean(cs:invite-noresponse)', $user)) {
+                $status = SharingPlugin::STATUS_NORESPONSE;
+            } elseif ($xpath->evaluate('boolean(cs:invite-invalid)', $user)) {
+                $status = SharingPlugin::STATUS_INVALID;
+            } else {
+                throw new DAV\Exception('Every cs:user property must have one of cs:invite-accepted, cs:invite-declined, cs:invite-noresponse or cs:invite-invalid');
+            }
+            $users[] = array(
+                'href' => $xpath->evaluate('string(d:href)', $user),
+                'commonName' => $xpath->evaluate('string(cs:common-name)', $user),
+                'readOnly' => $xpath->evaluate('boolean(cs:access/cs:read)', $user),
+                'summary' => $xpath->evaluate('string(cs:summary)', $user),
+                'status' => $status,
+            );
+
+        }
+
+        return new self($users);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/ScheduleCalendarTransp.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/ScheduleCalendarTransp.php
new file mode 100644
index 0000000..bf8f78a
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/ScheduleCalendarTransp.php
@@ -0,0 +1,102 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * schedule-calendar-transp property.
+ *
+ * This property is a representation of the schedule-calendar-transp property.
+ * This property is defined in RFC6638 (caldav scheduling).
+ *
+ * Its values are either 'transparent' or 'opaque'. If it's transparent, it
+ * means that this calendar will not be taken into consideration when a
+ * different user queries for free-busy information. If it's 'opaque', it will.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ScheduleCalendarTransp extends DAV\Property {
+
+    const TRANSPARENT = 'transparent';
+    const OPAQUE = 'opaque';
+
+    protected $value;
+
+    /**
+     * Creates the property
+     *
+     * @param string $value
+     */
+    public function __construct($value) {
+
+        if ($value !== self::TRANSPARENT && $value !== self::OPAQUE) {
+            throw new \InvalidArgumentException('The value must either be specified as "transparent" or "opaque"');
+        }
+        $this->value = $value;
+
+    }
+
+    /**
+     * Returns the current value
+     *
+     * @return string
+     */
+    public function getValue() {
+
+        return $this->value;
+
+    }
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+        switch($this->value) {
+            case self::TRANSPARENT :
+                $xval = $doc->createElement('cal:transparent');
+                break;
+            case self::OPAQUE :
+                $xval = $doc->createElement('cal:opaque');
+                break;
+        }
+
+        $node->appendChild($xval);
+
+    }
+
+    /**
+     * Unserializes the DOMElement back into a Property class.
+     *
+     * @param \DOMElement $node
+     * @return ScheduleCalendarTransp
+     */
+    static function unserialize(\DOMElement $node) {
+
+        $value = null;
+        foreach($node->childNodes as $childNode) {
+            switch(DAV\XMLUtil::toClarkNotation($childNode)) {
+                case '{' . CalDAV\Plugin::NS_CALDAV . '}opaque' :
+                    $value = self::OPAQUE;
+                    break;
+                case '{' . CalDAV\Plugin::NS_CALDAV . '}transparent' :
+                    $value = self::TRANSPARENT;
+                    break;
+            }
+        }
+        if (is_null($value))
+           return null;
+
+        return new self($value);
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarComponentSet.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarComponentSet.php
new file mode 100644
index 0000000..cd4b469
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarComponentSet.php
@@ -0,0 +1,88 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+
+/**
+ * Supported component set property
+ *
+ * This property is a representation of the supported-calendar_component-set
+ * property in the CalDAV namespace. It simply requires an array of components,
+ * such as VEVENT, VTODO
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedCalendarComponentSet extends DAV\Property {
+
+    /**
+     * List of supported components, such as "VEVENT, VTODO"
+     *
+     * @var array
+     */
+    private $components;
+
+    /**
+     * Creates the property
+     *
+     * @param array $components
+     */
+    public function __construct(array $components) {
+
+       $this->components = $components;
+
+    }
+
+    /**
+     * Returns the list of supported components
+     *
+     * @return array
+     */
+    public function getValue() {
+
+        return $this->components;
+
+    }
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+       $doc = $node->ownerDocument;
+       foreach($this->components as $component) {
+
+            $xcomp = $doc->createElement('cal:comp');
+            $xcomp->setAttribute('name',$component);
+            $node->appendChild($xcomp);
+
+       }
+
+    }
+
+    /**
+     * Unserializes the DOMElement back into a Property class.
+     *
+     * @param \DOMElement $node
+     * @return Property_SupportedCalendarComponentSet
+     */
+    static function unserialize(\DOMElement $node) {
+
+        $components = array();
+        foreach($node->childNodes as $childNode) {
+            if (DAV\XMLUtil::toClarkNotation($childNode)==='{' . CalDAV\Plugin::NS_CALDAV . '}comp') {
+                $components[] = $childNode->getAttribute('name');
+            }
+        }
+        return new self($components);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarData.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarData.php
new file mode 100644
index 0000000..fd358c6
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCalendarData.php
@@ -0,0 +1,40 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+use OldSabre\DAV;
+use OldSabre\CalDAV\Plugin;
+
+/**
+ * Supported-calendar-data property
+ *
+ * This property is a representation of the supported-calendar-data property
+ * in the CalDAV namespace. SabreDAV only has support for text/calendar;2.0
+ * so the value is currently hardcoded.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedCalendarData extends DAV\Property {
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+
+        $prefix = isset($server->xmlNamespaces[Plugin::NS_CALDAV])?$server->xmlNamespaces[Plugin::NS_CALDAV]:'cal';
+
+        $caldata = $doc->createElement($prefix . ':calendar-data');
+        $caldata->setAttribute('content-type','text/calendar');
+        $caldata->setAttribute('version','2.0');
+
+        $node->appendChild($caldata);
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCollationSet.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCollationSet.php
new file mode 100644
index 0000000..9a92c7c
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Property/SupportedCollationSet.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace OldSabre\CalDAV\Property;
+use OldSabre\DAV;
+
+/**
+ * supported-collation-set property
+ *
+ * This property is a representation of the supported-collation-set property
+ * in the CalDAV namespace.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedCollationSet extends DAV\Property {
+
+    /**
+     * Serializes the property in a DOM document
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+
+        $prefix = $node->lookupPrefix('urn:ietf:params:xml:ns:caldav');
+        if (!$prefix) $prefix = 'cal';
+
+        $node->appendChild(
+            $doc->createElement($prefix . ':supported-collation','i;ascii-casemap')
+        );
+        $node->appendChild(
+            $doc->createElement($prefix . ':supported-collation','i;octet')
+        );
+        $node->appendChild(
+            $doc->createElement($prefix . ':supported-collation','i;unicode-casemap')
+        );
+
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IMip.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IMip.php
new file mode 100644
index 0000000..5898917
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IMip.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace OldSabre\CalDAV\Schedule;
+
+use OldSabre\VObject;
+use OldSabre\DAV;
+
+/**
+ * iMIP handler.
+ *
+ * This class is responsible for sending out iMIP messages. iMIP is the
+ * email-based transport for iTIP. iTIP deals with scheduling operations for
+ * iCalendar objects.
+ *
+ * If you want to customize the email that gets sent out, you can do so by
+ * extending this class and overriding the sendMessage method.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class IMip {
+
+    /**
+     * Email address used in From: header.
+     *
+     * @var string
+     */
+    protected $senderEmail;
+
+    /**
+     * Creates the email handler.
+     *
+     * @param string $senderEmail. The 'senderEmail' is the email that shows up
+     *                             in the 'From:' address. This should
+     *                             generally be some kind of no-reply email
+     *                             address you own.
+     */
+    public function __construct($senderEmail) {
+
+        $this->senderEmail = $senderEmail;
+
+    }
+
+    /**
+     * Sends one or more iTip messages through email.
+     *
+     * @param string $originator Originator Email
+     * @param array $recipients Array of email addresses
+     * @param VObject\Component $vObject
+     * @param string $principal Principal Url of the originator
+     * @return void
+     */
+    public function sendMessage($originator, array $recipients, VObject\Component $vObject, $principal) {
+
+        foreach($recipients as $recipient) {
+
+            $to = $recipient;
+            $replyTo = $originator;
+            $subject = 'SabreDAV iTIP message';
+
+            switch(strtoupper($vObject->METHOD)) {
+                case 'REPLY' :
+                    $subject = 'Response for: ' . $vObject->VEVENT->SUMMARY;
+                    break;
+                case 'REQUEST' :
+                    $subject = 'Invitation for: ' .$vObject->VEVENT->SUMMARY;
+                    break;
+                case 'CANCEL' :
+                    $subject = 'Cancelled event: ' . $vObject->VEVENT->SUMMARY;
+                    break;
+            }
+
+            $headers = array();
+            $headers[] = 'Reply-To: ' . $replyTo;
+            $headers[] = 'From: ' . $this->senderEmail;
+            $headers[] = 'Content-Type: text/calendar; method=' . (string)$vObject->method . '; charset=utf-8';
+            if (DAV\Server::$exposeVersion) {
+                $headers[] = 'X-Sabre-Version: ' . DAV\Version::VERSION . '-' . DAV\Version::STABILITY;
+            }
+
+            $vcalBody = $vObject->serialize();
+
+            $this->mail($to, $subject, $vcalBody, $headers);
+
+        }
+
+    }
+
+    // @codeCoverageIgnoreStart
+    // This is deemed untestable in a reasonable manner
+
+    /**
+     * This function is reponsible for sending the actual email.
+     *
+     * @param string $to Recipient email address
+     * @param string $subject Subject of the email
+     * @param string $body iCalendar body
+     * @param array $headers List of headers
+     * @return void
+     */
+    protected function mail($to, $subject, $body, array $headers) {
+
+
+        mail($to, $subject, $body, implode("\r\n", $headers));
+
+    }
+
+    // @codeCoverageIgnoreEnd
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IOutbox.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IOutbox.php
new file mode 100644
index 0000000..5040ac9
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/IOutbox.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace OldSabre\CalDAV\Schedule;
+
+/**
+ * Implement this interface to have a node be recognized as a CalDAV scheduling
+ * outbox.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IOutbox extends \OldSabre\DAV\ICollection, \OldSabre\DAVACL\IACL {
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/Outbox.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/Outbox.php
new file mode 100644
index 0000000..dc67766
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Schedule/Outbox.php
@@ -0,0 +1,163 @@
+<?php
+
+namespace OldSabre\CalDAV\Schedule;
+use OldSabre\DAV;
+use OldSabre\CalDAV;
+use OldSabre\DAVACL;
+
+/**
+ * The CalDAV scheduling outbox
+ *
+ * The outbox is mainly used as an endpoint in the tree for a client to do
+ * free-busy requests. This functionality is completely handled by the
+ * Scheduling plugin, so this object is actually mostly static.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Outbox extends DAV\Collection implements IOutbox {
+
+    /**
+     * The principal Uri
+     *
+     * @var string
+     */
+    protected $principalUri;
+
+    /**
+     * Constructor
+     *
+     * @param string $principalUri
+     */
+    public function __construct($principalUri) {
+
+        $this->principalUri = $principalUri;
+
+    }
+
+    /**
+     * Returns the name of the node.
+     *
+     * This is used to generate the url.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return 'outbox';
+
+    }
+
+    /**
+     * Returns an array with all the child nodes
+     *
+     * @return \OldSabre\DAV\INode[]
+     */
+    public function getChildren() {
+
+        return array();
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalUri;
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-query-freebusy',
+                'principal' => $this->getOwner(),
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-post-vevent',
+                'principal' => $this->getOwner(),
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->getOwner(),
+                'protected' => true,
+            ),
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('You\'re not allowed to update the ACL');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        $default = DAVACL\Plugin::getDefaultSupportedPrivilegeSet();
+        $default['aggregates'][] = array(
+            'privilege' => '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-query-freebusy',
+        );
+        $default['aggregates'][] = array(
+            'privilege' => '{' . CalDAV\Plugin::NS_CALDAV . '}schedule-post-vevent',
+        );
+
+        return $default;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ShareableCalendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ShareableCalendar.php
new file mode 100644
index 0000000..2e8f440
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/ShareableCalendar.php
@@ -0,0 +1,72 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+/**
+ * This object represents a CalDAV calendar that can be shared with other
+ * users.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ShareableCalendar extends Calendar implements IShareableCalendar {
+
+    /**
+     * Updates the list of shares.
+     *
+     * The first array is a list of people that are to be added to the
+     * calendar.
+     *
+     * Every element in the add array has the following properties:
+     *   * href - A url. Usually a mailto: address
+     *   * commonName - Usually a first and last name, or false
+     *   * summary - A description of the share, can also be false
+     *   * readOnly - A boolean value
+     *
+     * Every element in the remove array is just the address string.
+     *
+     * @param array $add
+     * @param array $remove
+     * @return void
+     */
+    public function updateShares(array $add, array $remove) {
+
+        $this->caldavBackend->updateShares($this->calendarInfo['id'], $add, $remove);
+
+    }
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the OldSabre\CalDAV\SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * @return array
+     */
+    public function getShares() {
+
+        return $this->caldavBackend->getShares($this->calendarInfo['id']);
+
+    }
+
+    /**
+     * Marks this calendar as published.
+     *
+     * Publishing a calendar should automatically create a read-only, public,
+     * subscribable calendar.
+     *
+     * @param bool $value
+     * @return void
+     */
+    public function setPublishStatus($value) {
+
+        $this->caldavBackend->setPublishStatus($this->calendarInfo['id'], $value);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharedCalendar.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharedCalendar.php
new file mode 100644
index 0000000..5586419
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharedCalendar.php
@@ -0,0 +1,116 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAVACL;
+
+/**
+ * This object represents a CalDAV calendar that is shared by a different user.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SharedCalendar extends Calendar implements ISharedCalendar {
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $caldavBackend
+     * @param array $calendarInfo
+     */
+    public function __construct(Backend\BackendInterface $caldavBackend, $calendarInfo) {
+
+        $required = array(
+            '{http://calendarserver.org/ns/}shared-url',
+            '{http://sabredav.org/ns}owner-principal',
+            '{http://sabredav.org/ns}read-only',
+        );
+        foreach($required as $r) {
+            if (!isset($calendarInfo[$r])) {
+                throw new \InvalidArgumentException('The ' . $r . ' property must be specified for SharedCalendar(s)');
+            }
+        }
+
+        parent::__construct($caldavBackend, $calendarInfo);
+
+    }
+
+    /**
+     * This method should return the url of the owners' copy of the shared
+     * calendar.
+     *
+     * @return string
+     */
+    public function getSharedUrl() {
+
+        return $this->calendarInfo['{http://calendarserver.org/ns/}shared-url'];
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->calendarInfo['{http://sabredav.org/ns}owner-principal'];
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        // The top-level ACL only contains access information for the true
+        // owner of the calendar, so we need to add the information for the
+        // sharee.
+        $acl = parent::getACL();
+        $acl[] = array(
+            'privilege' => '{DAV:}read',
+            'principal' => $this->calendarInfo['principaluri'],
+            'protected' => true,
+        );
+        if (!$this->calendarInfo['{http://sabredav.org/ns}read-only']) {
+            $acl[] = array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->calendarInfo['principaluri'],
+                'protected' => true,
+            );
+        }
+        return $acl;
+
+    }
+
+    /**
+     * Returns the list of people whom this calendar is shared with.
+     *
+     * Every element in this array should have the following properties:
+     *   * href - Often a mailto: address
+     *   * commonName - Optional, for example a first + last name
+     *   * status - See the OldSabre\CalDAV\SharingPlugin::STATUS_ constants.
+     *   * readOnly - boolean
+     *   * summary - Optional, a description for the share
+     *
+     * @return array
+     */
+    public function getShares() {
+
+        return $this->caldavBackend->getShares($this->calendarInfo['id']);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharingPlugin.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharingPlugin.php
new file mode 100644
index 0000000..92942c0
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/SharingPlugin.php
@@ -0,0 +1,526 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAV;
+
+/**
+ * This plugin implements support for caldav sharing.
+ *
+ * This spec is defined at:
+ * http://svn.calendarserver.org/repository/calendarserver/CalendarServer/trunk/doc/Extensions/caldav-sharing.txt
+ *
+ * See:
+ * OldSabre\CalDAV\Backend\SharingSupport for all the documentation.
+ *
+ * Note: This feature is experimental, and may change in between different
+ * SabreDAV versions.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SharingPlugin extends DAV\ServerPlugin {
+
+    /**
+     * These are the various status constants used by sharing-messages.
+     */
+    const STATUS_ACCEPTED = 1;
+    const STATUS_DECLINED = 2;
+    const STATUS_DELETED = 3;
+    const STATUS_NORESPONSE = 4;
+    const STATUS_INVALID = 5;
+
+    /**
+     * Reference to SabreDAV server object.
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * This method should return a list of server-features.
+     *
+     * This is for example 'versioning' and is added to the DAV: header
+     * in an OPTIONS response.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array('calendarserver-sharing');
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using OldSabre\DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'caldav-sharing';
+
+    }
+
+    /**
+     * This initializes the plugin.
+     *
+     * This function is called by OldSabre\DAV\Server, after
+     * addPlugin is called.
+     *
+     * This method should set up the required event subscriptions.
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $server->resourceTypeMapping['OldSabre\\CalDAV\\ISharedCalendar'] = '{' . Plugin::NS_CALENDARSERVER . '}shared';
+
+        array_push(
+            $this->server->protectedProperties,
+            '{' . Plugin::NS_CALENDARSERVER . '}invite',
+            '{' . Plugin::NS_CALENDARSERVER . '}allowed-sharing-modes',
+            '{' . Plugin::NS_CALENDARSERVER . '}shared-url'
+        );
+
+        $this->server->subscribeEvent('beforeGetProperties', array($this, 'beforeGetProperties'));
+        $this->server->subscribeEvent('afterGetProperties', array($this, 'afterGetProperties'));
+        $this->server->subscribeEvent('updateProperties', array($this, 'updateProperties'));
+        $this->server->subscribeEvent('unknownMethod', array($this,'unknownMethod'));
+
+    }
+
+    /**
+     * This event is triggered when properties are requested for a certain
+     * node.
+     *
+     * This allows us to inject any properties early.
+     *
+     * @param string $path
+     * @param DAV\INode $node
+     * @param array $requestedProperties
+     * @param array $returnedProperties
+     * @return void
+     */
+    public function beforeGetProperties($path, DAV\INode $node, &$requestedProperties, &$returnedProperties) {
+
+        if ($node instanceof IShareableCalendar) {
+            if (($index = array_search('{' . Plugin::NS_CALENDARSERVER . '}invite', $requestedProperties))!==false) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{' . Plugin::NS_CALENDARSERVER . '}invite'] =
+                    new Property\Invite(
+                        $node->getShares()
+                    );
+
+            }
+
+        }
+
+        if ($node instanceof ISharedCalendar) {
+
+            if (($index = array_search('{' . Plugin::NS_CALENDARSERVER . '}shared-url', $requestedProperties))!==false) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{' . Plugin::NS_CALENDARSERVER . '}shared-url'] =
+                    new DAV\Property\Href(
+                        $node->getSharedUrl()
+                    );
+
+            }
+            // The 'invite' property is slightly different for the 'shared'
+            // instance of the calendar, as it also contains the owner
+            // information.
+            if (($index = array_search('{' . Plugin::NS_CALENDARSERVER . '}invite', $requestedProperties))!==false) {
+
+                unset($requestedProperties[$index]);
+
+                // Fetching owner information
+                $props = $this->server->getPropertiesForPath($node->getOwner(), array(
+                    '{http://sabredav.org/ns}email-address',
+                    '{DAV:}displayname',
+                ), 1);
+
+                $ownerInfo = array(
+                    'href' => $node->getOwner(),
+                );
+
+                if (isset($props[0][200])) {
+
+                    // We're mapping the internal webdav properties to the
+                    // elements caldav-sharing expects.
+                    if (isset($props[0][200]['{http://sabredav.org/ns}email-address'])) {
+                        $ownerInfo['href'] = 'mailto:' . $props[0][200]['{http://sabredav.org/ns}email-address'];
+                    }
+                    if (isset($props[0][200]['{DAV:}displayname'])) {
+                        $ownerInfo['commonName'] = $props[0][200]['{DAV:}displayname'];
+                    }
+
+                }
+
+                $returnedProperties[200]['{' . Plugin::NS_CALENDARSERVER . '}invite'] =
+                    new Property\Invite(
+                        $node->getShares(),
+                        $ownerInfo
+                    );
+
+            }
+
+
+        }
+
+    }
+
+    /**
+     * This method is triggered *after* all properties have been retrieved.
+     * This allows us to inject the correct resourcetype for calendars that
+     * have been shared.
+     *
+     * @param string $path
+     * @param array $properties
+     * @param DAV\INode $node
+     * @return void
+     */
+    public function afterGetProperties($path, &$properties, DAV\INode $node) {
+
+        if ($node instanceof IShareableCalendar) {
+            if (isset($properties[200]['{DAV:}resourcetype'])) {
+                if (count($node->getShares())>0) {
+                    $properties[200]['{DAV:}resourcetype']->add(
+                        '{' . Plugin::NS_CALENDARSERVER . '}shared-owner'
+                    );
+                }
+            }
+            $propName = '{' . Plugin::NS_CALENDARSERVER . '}allowed-sharing-modes';
+            if (array_key_exists($propName, $properties[404])) {
+                unset($properties[404][$propName]);
+                $properties[200][$propName] = new Property\AllowedSharingModes(true,false);
+            }
+
+        }
+
+    }
+
+    /**
+     * This method is trigged when a user attempts to update a node's
+     * properties.
+     *
+     * A previous draft of the sharing spec stated that it was possible to use
+     * PROPPATCH to remove 'shared-owner' from the resourcetype, thus unsharing
+     * the calendar.
+     *
+     * Even though this is no longer in the current spec, we keep this around
+     * because OS X 10.7 may still make use of this feature.
+     *
+     * @param array $mutations
+     * @param array $result
+     * @param DAV\INode $node
+     * @return void
+     */
+    public function updateProperties(array &$mutations, array &$result, DAV\INode $node) {
+
+        if (!$node instanceof IShareableCalendar)
+            return;
+
+        if (!isset($mutations['{DAV:}resourcetype'])) {
+            return;
+        }
+
+        // Only doing something if shared-owner is indeed not in the list.
+        if($mutations['{DAV:}resourcetype']->is('{' . Plugin::NS_CALENDARSERVER . '}shared-owner')) return;
+
+        $shares = $node->getShares();
+        $remove = array();
+        foreach($shares as $share) {
+            $remove[] = $share['href'];
+        }
+        $node->updateShares(array(), $remove);
+
+        // We're marking this update as 200 OK
+        $result[200]['{DAV:}resourcetype'] = null;
+
+        // Removing it from the mutations list
+        unset($mutations['{DAV:}resourcetype']);
+
+    }
+
+    /**
+     * This event is triggered when the server didn't know how to handle a
+     * certain request.
+     *
+     * We intercept this to handle POST requests on calendars.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return null|bool
+     */
+    public function unknownMethod($method, $uri) {
+
+        if ($method!=='POST') {
+            return;
+        }
+
+        // Only handling xml
+        $contentType = $this->server->httpRequest->getHeader('Content-Type');
+        if (strpos($contentType,'application/xml')===false && strpos($contentType,'text/xml')===false)
+            return;
+
+        // Making sure the node exists
+        try {
+            $node = $this->server->tree->getNodeForPath($uri);
+        } catch (DAV\Exception\NotFound $e) {
+            return;
+        }
+
+        $requestBody = $this->server->httpRequest->getBody(true);
+
+        // If this request handler could not deal with this POST request, it
+        // will return 'null' and other plugins get a chance to handle the
+        // request.
+        //
+        // However, we already requested the full body. This is a problem,
+        // because a body can only be read once. This is why we preemptively
+        // re-populated the request body with the existing data.
+        $this->server->httpRequest->setBody($requestBody);
+
+        $dom = DAV\XMLUtil::loadDOMDocument($requestBody);
+
+        $documentType = DAV\XMLUtil::toClarkNotation($dom->firstChild);
+
+        switch($documentType) {
+
+            // Dealing with the 'share' document, which modified invitees on a
+            // calendar.
+            case '{' . Plugin::NS_CALENDARSERVER . '}share' :
+
+                // We can only deal with IShareableCalendar objects
+                if (!$node instanceof IShareableCalendar) {
+                    return;
+                }
+
+                // Getting ACL info
+                $acl = $this->server->getPlugin('acl');
+
+                // If there's no ACL support, we allow everything
+                if ($acl) {
+                    $acl->checkPrivileges($uri, '{DAV:}write');
+                }
+
+                $mutations = $this->parseShareRequest($dom);
+
+                $node->updateShares($mutations[0], $mutations[1]);
+
+                $this->server->httpResponse->sendStatus(200);
+                // Adding this because sending a response body may cause issues,
+                // and I wanted some type of indicator the response was handled.
+                $this->server->httpResponse->setHeader('X-Sabre-Status', 'everything-went-well');
+
+                // Breaking the event chain
+                return false;
+
+            // The invite-reply document is sent when the user replies to an
+            // invitation of a calendar share.
+            case '{'. Plugin::NS_CALENDARSERVER.'}invite-reply' :
+
+                // This only works on the calendar-home-root node.
+                if (!$node instanceof UserCalendars) {
+                    return;
+                }
+
+                // Getting ACL info
+                $acl = $this->server->getPlugin('acl');
+
+                // If there's no ACL support, we allow everything
+                if ($acl) {
+                    $acl->checkPrivileges($uri, '{DAV:}write');
+                }
+
+                $message = $this->parseInviteReplyRequest($dom);
+
+                $url = $node->shareReply(
+                    $message['href'],
+                    $message['status'],
+                    $message['calendarUri'],
+                    $message['inReplyTo'],
+                    $message['summary']
+                );
+
+                $this->server->httpResponse->sendStatus(200);
+                // Adding this because sending a response body may cause issues,
+                // and I wanted some type of indicator the response was handled.
+                $this->server->httpResponse->setHeader('X-Sabre-Status', 'everything-went-well');
+
+                if ($url) {
+                    $dom = new \DOMDocument('1.0', 'UTF-8');
+                    $dom->formatOutput = true;
+
+                    $root = $dom->createElement('cs:shared-as');
+                    foreach($this->server->xmlNamespaces as $namespace => $prefix) {
+                        $root->setAttribute('xmlns:' . $prefix, $namespace);
+                    }
+
+                    $dom->appendChild($root);
+                    $href = new DAV\Property\Href($url);
+
+                    $href->serialize($this->server, $root);
+                    $this->server->httpResponse->setHeader('Content-Type','application/xml');
+                    $this->server->httpResponse->sendBody($dom->saveXML());
+
+                }
+
+                // Breaking the event chain
+                return false;
+
+            case '{' . Plugin::NS_CALENDARSERVER . '}publish-calendar' :
+
+                // We can only deal with IShareableCalendar objects
+                if (!$node instanceof IShareableCalendar) {
+                    return;
+                }
+
+                // Getting ACL info
+                $acl = $this->server->getPlugin('acl');
+
+                // If there's no ACL support, we allow everything
+                if ($acl) {
+                    $acl->checkPrivileges($uri, '{DAV:}write');
+                }
+
+                $node->setPublishStatus(true);
+
+                // iCloud sends back the 202, so we will too.
+                $this->server->httpResponse->sendStatus(202);
+
+                // Adding this because sending a response body may cause issues,
+                // and I wanted some type of indicator the response was handled.
+                $this->server->httpResponse->setHeader('X-Sabre-Status', 'everything-went-well');
+
+                // Breaking the event chain
+                return false;
+
+            case '{' . Plugin::NS_CALENDARSERVER . '}unpublish-calendar' :
+
+                // We can only deal with IShareableCalendar objects
+                if (!$node instanceof IShareableCalendar) {
+                    return;
+                }
+
+                // Getting ACL info
+                $acl = $this->server->getPlugin('acl');
+
+                // If there's no ACL support, we allow everything
+                if ($acl) {
+                    $acl->checkPrivileges($uri, '{DAV:}write');
+                }
+
+                $node->setPublishStatus(false);
+
+                $this->server->httpResponse->sendStatus(200);
+
+                // Adding this because sending a response body may cause issues,
+                // and I wanted some type of indicator the response was handled.
+                $this->server->httpResponse->setHeader('X-Sabre-Status', 'everything-went-well');
+
+                // Breaking the event chain
+                return false;
+
+        }
+
+
+
+    }
+
+    /**
+     * Parses the 'share' POST request.
+     *
+     * This method returns an array, containing two arrays.
+     * The first array is a list of new sharees. Every element is a struct
+     * containing a:
+     *   * href element. (usually a mailto: address)
+     *   * commonName element (often a first and lastname, but can also be
+     *     false)
+     *   * readOnly (true or false)
+     *   * summary (A description of the share, can also be false)
+     *
+     * The second array is a list of sharees that are to be removed. This is
+     * just a simple array with 'hrefs'.
+     *
+     * @param \DOMDocument $dom
+     * @return array
+     */
+    protected function parseShareRequest(\DOMDocument $dom) {
+
+        $xpath = new \DOMXPath($dom);
+        $xpath->registerNamespace('cs', Plugin::NS_CALENDARSERVER);
+        $xpath->registerNamespace('d', 'urn:DAV');
+
+        $set = array();
+        $elems = $xpath->query('cs:set');
+
+        for($i=0; $i < $elems->length; $i++) {
+
+            $xset = $elems->item($i);
+            $set[] = array(
+                'href' => $xpath->evaluate('string(d:href)', $xset),
+                'commonName' => $xpath->evaluate('string(cs:common-name)', $xset),
+                'summary' => $xpath->evaluate('string(cs:summary)', $xset),
+                'readOnly' => $xpath->evaluate('boolean(cs:read)', $xset)!==false
+            );
+
+        }
+
+        $remove = array();
+        $elems = $xpath->query('cs:remove');
+
+        for($i=0; $i < $elems->length; $i++) {
+
+            $xremove = $elems->item($i);
+            $remove[] = $xpath->evaluate('string(d:href)', $xremove);
+
+        }
+
+        return array($set, $remove);
+
+    }
+
+    /**
+     * Parses the 'invite-reply' POST request.
+     *
+     * This method returns an array, containing the following properties:
+     *   * href - The sharee who is replying
+     *   * status - One of the self::STATUS_* constants
+     *   * calendarUri - The url of the shared calendar
+     *   * inReplyTo - The unique id of the share invitation.
+     *   * summary - Optional description of the reply.
+     *
+     * @param \DOMDocument $dom
+     * @return array
+     */
+    protected function parseInviteReplyRequest(\DOMDocument $dom) {
+
+        $xpath = new \DOMXPath($dom);
+        $xpath->registerNamespace('cs', Plugin::NS_CALENDARSERVER);
+        $xpath->registerNamespace('d', 'urn:DAV');
+
+        $hostHref = $xpath->evaluate('string(cs:hosturl/d:href)');
+        if (!$hostHref) {
+            throw new DAV\Exception\BadRequest('The {' . Plugin::NS_CALENDARSERVER . '}hosturl/{DAV:}href element is required');
+        }
+
+        return array(
+            'href' => $xpath->evaluate('string(d:href)'),
+            'calendarUri' => $this->server->calculateUri($hostHref),
+            'inReplyTo' => $xpath->evaluate('string(cs:in-reply-to)'),
+            'summary' => $xpath->evaluate('string(cs:summary)'),
+            'status' => $xpath->evaluate('boolean(cs:invite-accepted)')?self::STATUS_ACCEPTED:self::STATUS_DECLINED
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/UserCalendars.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/UserCalendars.php
new file mode 100644
index 0000000..a4fbc66
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/UserCalendars.php
@@ -0,0 +1,342 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * The UserCalenders class contains all calendars associated to one user
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class UserCalendars implements DAV\IExtendedCollection, DAVACL\IACL {
+
+    /**
+     * CalDAV backend
+     *
+     * @var OldSabre\CalDAV\Backend\BackendInterface
+     */
+    protected $caldavBackend;
+
+    /**
+     * Principal information
+     *
+     * @var array
+     */
+    protected $principalInfo;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $caldavBackend
+     * @param mixed $userUri
+     */
+    public function __construct(Backend\BackendInterface $caldavBackend, $principalInfo) {
+
+        $this->caldavBackend = $caldavBackend;
+        $this->principalInfo = $principalInfo;
+
+    }
+
+    /**
+     * Returns the name of this object
+     *
+     * @return string
+     */
+    public function getName() {
+
+        list(,$name) = DAV\URLUtil::splitPath($this->principalInfo['uri']);
+        return $name;
+
+    }
+
+    /**
+     * Updates the name of this object
+     *
+     * @param string $name
+     * @return void
+     */
+    public function setName($name) {
+
+        throw new DAV\Exception\Forbidden();
+
+    }
+
+    /**
+     * Deletes this object
+     *
+     * @return void
+     */
+    public function delete() {
+
+        throw new DAV\Exception\Forbidden();
+
+    }
+
+    /**
+     * Returns the last modification date
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Creates a new file under this object.
+     *
+     * This is currently not allowed
+     *
+     * @param string $filename
+     * @param resource $data
+     * @return void
+     */
+    public function createFile($filename, $data=null) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating new files in this collection is not supported');
+
+    }
+
+    /**
+     * Creates a new directory under this object.
+     *
+     * This is currently not allowed.
+     *
+     * @param string $filename
+     * @return void
+     */
+    public function createDirectory($filename) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating new collections in this collection is not supported');
+
+    }
+
+    /**
+     * Returns a single calendar, by name
+     *
+     * @param string $name
+     * @todo needs optimizing
+     * @return Calendar
+     */
+    public function getChild($name) {
+
+        foreach($this->getChildren() as $child) {
+            if ($name==$child->getName())
+                return $child;
+
+        }
+        throw new DAV\Exception\NotFound('Calendar with name \'' . $name . '\' could not be found');
+
+    }
+
+    /**
+     * Checks if a calendar exists.
+     *
+     * @param string $name
+     * @todo needs optimizing
+     * @return bool
+     */
+    public function childExists($name) {
+
+        foreach($this->getChildren() as $child) {
+            if ($name==$child->getName())
+                return true;
+
+        }
+        return false;
+
+    }
+
+    /**
+     * Returns a list of calendars
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        $calendars = $this->caldavBackend->getCalendarsForUser($this->principalInfo['uri']);
+        $objs = array();
+        foreach($calendars as $calendar) {
+            if ($this->caldavBackend instanceof Backend\SharingSupport) {
+                if (isset($calendar['{http://calendarserver.org/ns/}shared-url'])) {
+                    $objs[] = new SharedCalendar($this->caldavBackend, $calendar);
+                } else {
+                    $objs[] = new ShareableCalendar($this->caldavBackend, $calendar);
+                }
+            } else {
+                $objs[] = new Calendar($this->caldavBackend, $calendar);
+            }
+        }
+        $objs[] = new Schedule\Outbox($this->principalInfo['uri']);
+
+        // We're adding a notifications node, if it's supported by the backend.
+        if ($this->caldavBackend instanceof Backend\NotificationSupport) {
+            $objs[] = new Notifications\Collection($this->caldavBackend, $this->principalInfo['uri']);
+        }
+        return $objs;
+
+    }
+
+    /**
+     * Creates a new calendar
+     *
+     * @param string $name
+     * @param array $resourceType
+     * @param array $properties
+     * @return void
+     */
+    public function createExtendedCollection($name, array $resourceType, array $properties) {
+
+        $isCalendar = false;
+        foreach($resourceType as $rt) {
+            switch ($rt) {
+                case '{DAV:}collection' :
+                case '{http://calendarserver.org/ns/}shared-owner' :
+                    // ignore
+                    break;
+                case '{urn:ietf:params:xml:ns:caldav}calendar' :
+                    $isCalendar = true;
+                    break;
+                default :
+                    throw new DAV\Exception\InvalidResourceType('Unknown resourceType: ' . $rt);
+            }
+        }
+        if (!$isCalendar) {
+            throw new DAV\Exception\InvalidResourceType('You can only create calendars in this collection');
+        }
+        $this->caldavBackend->createCalendar($this->principalInfo['uri'], $name, $properties);
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalInfo['uri'];
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->principalInfo['uri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->principalInfo['uri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->principalInfo['uri'] . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->principalInfo['uri'] . '/calendar-proxy-write',
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->principalInfo['uri'] . '/calendar-proxy-read',
+                'protected' => true,
+            ),
+
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+    /**
+     * This method is called when a user replied to a request to share.
+     *
+     * This method should return the url of the newly created calendar if the
+     * share was accepted.
+     *
+     * @param string href The sharee who is replying (often a mailto: address)
+     * @param int status One of the SharingPlugin::STATUS_* constants
+     * @param string $calendarUri The url to the calendar thats being shared
+     * @param string $inReplyTo The unique id this message is a response to
+     * @param string $summary A description of the reply
+     * @return null|string
+     */
+    public function shareReply($href, $status, $calendarUri, $inReplyTo, $summary = null) {
+
+        if (!$this->caldavBackend instanceof Backend\SharingSupport) {
+            throw new DAV\Exception\NotImplemented('Sharing support is not implemented by this backend.');
+        }
+
+        return $this->caldavBackend->shareReply($href, $status, $calendarUri, $inReplyTo, $summary);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Version.php b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Version.php
new file mode 100644
index 0000000..ead559a
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CalDAV/Version.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\CalDAV;
+
+/**
+ * This class contains the OldSabre\CalDAV version constants.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '1.8.7';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBook.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBook.php
new file mode 100644
index 0000000..250c0db
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBook.php
@@ -0,0 +1,315 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * The AddressBook class represents a CardDAV addressbook, owned by a specific user
+ *
+ * The AddressBook can contain multiple vcards
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AddressBook extends DAV\Collection implements IAddressBook, DAV\IProperties, DAVACL\IACL {
+
+    /**
+     * This is an array with addressbook information
+     *
+     * @var array
+     */
+    protected $addressBookInfo;
+
+    /**
+     * CardDAV backend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $carddavBackend;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $carddavBackend
+     * @param array $addressBookInfo
+     */
+    public function __construct(Backend\BackendInterface $carddavBackend, array $addressBookInfo) {
+
+        $this->carddavBackend = $carddavBackend;
+        $this->addressBookInfo = $addressBookInfo;
+
+    }
+
+    /**
+     * Returns the name of the addressbook
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->addressBookInfo['uri'];
+
+    }
+
+    /**
+     * Returns a card
+     *
+     * @param string $name
+     * @return \ICard
+     */
+    public function getChild($name) {
+
+        $obj = $this->carddavBackend->getCard($this->addressBookInfo['id'],$name);
+        if (!$obj) throw new DAV\Exception\NotFound('Card not found');
+        return new Card($this->carddavBackend,$this->addressBookInfo,$obj);
+
+    }
+
+    /**
+     * Returns the full list of cards
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        $objs = $this->carddavBackend->getCards($this->addressBookInfo['id']);
+        $children = array();
+        foreach($objs as $obj) {
+            $children[] = new Card($this->carddavBackend,$this->addressBookInfo,$obj);
+        }
+        return $children;
+
+    }
+
+    /**
+     * Creates a new directory
+     *
+     * We actually block this, as subdirectories are not allowed in addressbooks.
+     *
+     * @param string $name
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating collections in addressbooks is not allowed');
+
+    }
+
+    /**
+     * Creates a new file
+     *
+     * The contents of the new file must be a valid VCARD.
+     *
+     * This method may return an ETag.
+     *
+     * @param string $name
+     * @param resource $vcardData
+     * @return string|null
+     */
+    public function createFile($name,$vcardData = null) {
+
+        if (is_resource($vcardData)) {
+            $vcardData = stream_get_contents($vcardData);
+        }
+        // Converting to UTF-8, if needed
+        $vcardData = DAV\StringUtil::ensureUTF8($vcardData);
+
+        return $this->carddavBackend->createCard($this->addressBookInfo['id'],$name,$vcardData);
+
+    }
+
+    /**
+     * Deletes the entire addressbook.
+     *
+     * @return void
+     */
+    public function delete() {
+
+        $this->carddavBackend->deleteAddressBook($this->addressBookInfo['id']);
+
+    }
+
+    /**
+     * Renames the addressbook
+     *
+     * @param string $newName
+     * @return void
+     */
+    public function setName($newName) {
+
+        throw new DAV\Exception\MethodNotAllowed('Renaming addressbooks is not yet supported');
+
+    }
+
+    /**
+     * Returns the last modification date as a unix timestamp.
+     *
+     * @return void
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Updates properties on this node,
+     *
+     * The properties array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param array $mutations
+     * @return bool|array
+     */
+    public function updateProperties($mutations) {
+
+        return $this->carddavBackend->updateAddressBook($this->addressBookInfo['id'], $mutations);
+
+    }
+
+    /**
+     * Returns a list of properties for this nodes.
+     *
+     * The properties list is a list of propertynames the client requested,
+     * encoded in clark-notation {xmlnamespace}tagname
+     *
+     * If the array is empty, it means 'all properties' were requested.
+     *
+     * @param array $properties
+     * @return array
+     */
+    public function getProperties($properties) {
+
+        $response = array();
+        foreach($properties as $propertyName) {
+
+            if (isset($this->addressBookInfo[$propertyName])) {
+
+                $response[$propertyName] = $this->addressBookInfo[$propertyName];
+
+            }
+
+        }
+
+        return $response;
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->addressBookInfo['principaluri'];
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->addressBookInfo['principaluri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->addressBookInfo['principaluri'],
+                'protected' => true,
+            ),
+
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookQueryParser.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookQueryParser.php
new file mode 100644
index 0000000..e754147
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookQueryParser.php
@@ -0,0 +1,221 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+
+/**
+ * Parses the addressbook-query report request body.
+ *
+ * Whoever designed this format, and the CalDAV equivalent even more so,
+ * has no feel for design.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AddressBookQueryParser {
+
+    const TEST_ANYOF = 'anyof';
+    const TEST_ALLOF = 'allof';
+
+    /**
+     * List of requested properties the client wanted
+     *
+     * @var array
+     */
+    public $requestedProperties;
+
+    /**
+     * The number of results the client wants
+     *
+     * null means it wasn't specified, which in most cases means 'all results'.
+     *
+     * @var int|null
+     */
+    public $limit;
+
+    /**
+     * List of property filters.
+     *
+     * @var array
+     */
+    public $filters;
+
+    /**
+     * Either TEST_ANYOF or TEST_ALLOF
+     *
+     * @var string
+     */
+    public $test;
+
+    /**
+     * DOM Document
+     *
+     * @var DOMDocument
+     */
+    protected $dom;
+
+    /**
+     * DOM XPath object
+     *
+     * @var DOMXPath
+     */
+    protected $xpath;
+
+    /**
+     * Creates the parser
+     *
+     * @param \DOMDocument $dom
+     */
+    public function __construct(\DOMDocument $dom) {
+
+        $this->dom = $dom;
+
+        $this->xpath = new \DOMXPath($dom);
+        $this->xpath->registerNameSpace('card',Plugin::NS_CARDDAV);
+
+    }
+
+    /**
+     * Parses the request.
+     *
+     * @return void
+     */
+    public function parse() {
+
+        $filterNode = null;
+
+        $limit = $this->xpath->evaluate('number(/card:addressbook-query/card:limit/card:nresults)');
+        if (is_nan($limit)) $limit = null;
+
+        $filter = $this->xpath->query('/card:addressbook-query/card:filter');
+
+        // According to the CardDAV spec there needs to be exactly 1 filter
+        // element. However, KDE 4.8.2 contains a bug that will encode 0 filter
+        // elements, so this is a workaround for that.
+        //
+        // See: https://bugs.kde.org/show_bug.cgi?id=300047
+        if ($filter->length === 0) {
+            $test = null;
+            $filter = null;
+        } elseif ($filter->length === 1) {
+            $filter = $filter->item(0);
+            $test = $this->xpath->evaluate('string(@test)', $filter);
+        } else {
+            throw new DAV\Exception\BadRequest('Only one filter element is allowed');
+        }
+
+        if (!$test) $test = self::TEST_ANYOF;
+        if ($test !== self::TEST_ANYOF && $test !== self::TEST_ALLOF) {
+            throw new DAV\Exception\BadRequest('The test attribute must either hold "anyof" or "allof"');
+        }
+
+        $propFilters = array();
+
+        $propFilterNodes = $this->xpath->query('card:prop-filter', $filter);
+        for($ii=0; $ii < $propFilterNodes->length; $ii++) {
+
+            $propFilters[] = $this->parsePropFilterNode($propFilterNodes->item($ii));
+
+
+        }
+
+        $this->filters = $propFilters;
+        $this->limit = $limit;
+        $this->requestedProperties = array_keys(DAV\XMLUtil::parseProperties($this->dom->firstChild));
+        $this->test = $test;
+
+    }
+
+    /**
+     * Parses the prop-filter xml element
+     *
+     * @param \DOMElement $propFilterNode
+     * @return array
+     */
+    protected function parsePropFilterNode(\DOMElement $propFilterNode) {
+
+        $propFilter = array();
+        $propFilter['name'] = $propFilterNode->getAttribute('name');
+        $propFilter['test'] = $propFilterNode->getAttribute('test');
+        if (!$propFilter['test']) $propFilter['test'] = 'anyof';
+
+        $propFilter['is-not-defined'] = $this->xpath->query('card:is-not-defined', $propFilterNode)->length>0;
+
+        $paramFilterNodes = $this->xpath->query('card:param-filter', $propFilterNode);
+
+        $propFilter['param-filters'] = array();
+
+
+        for($ii=0;$ii<$paramFilterNodes->length;$ii++) {
+
+            $propFilter['param-filters'][] = $this->parseParamFilterNode($paramFilterNodes->item($ii));
+
+        }
+        $propFilter['text-matches'] = array();
+        $textMatchNodes = $this->xpath->query('card:text-match', $propFilterNode);
+
+        for($ii=0;$ii<$textMatchNodes->length;$ii++) {
+
+            $propFilter['text-matches'][] = $this->parseTextMatchNode($textMatchNodes->item($ii));
+
+        }
+
+        return $propFilter;
+
+    }
+
+    /**
+     * Parses the param-filter element
+     *
+     * @param \DOMElement $paramFilterNode
+     * @return array
+     */
+    public function parseParamFilterNode(\DOMElement $paramFilterNode) {
+
+        $paramFilter = array();
+        $paramFilter['name'] = $paramFilterNode->getAttribute('name');
+        $paramFilter['is-not-defined'] = $this->xpath->query('card:is-not-defined', $paramFilterNode)->length>0;
+        $paramFilter['text-match'] = null;
+
+        $textMatch = $this->xpath->query('card:text-match', $paramFilterNode);
+        if ($textMatch->length>0) {
+            $paramFilter['text-match'] = $this->parseTextMatchNode($textMatch->item(0));
+        }
+
+        return $paramFilter;
+
+    }
+
+    /**
+     * Text match
+     *
+     * @param \DOMElement $textMatchNode
+     * @return array
+     */
+    public function parseTextMatchNode(\DOMElement $textMatchNode) {
+
+        $matchType = $textMatchNode->getAttribute('match-type');
+        if (!$matchType) $matchType = 'contains';
+
+        if (!in_array($matchType, array('contains', 'equals', 'starts-with', 'ends-with'))) {
+            throw new DAV\Exception\BadRequest('Unknown match-type: ' . $matchType);
+        }
+
+        $negateCondition = $textMatchNode->getAttribute('negate-condition');
+        $negateCondition = $negateCondition==='yes';
+        $collation = $textMatchNode->getAttribute('collation');
+        if (!$collation) $collation = 'i;unicode-casemap';
+
+        return array(
+            'negate-condition' => $negateCondition,
+            'collation' => $collation,
+            'match-type' => $matchType,
+            'value' => $textMatchNode->nodeValue
+        );
+
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookRoot.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookRoot.php
new file mode 100644
index 0000000..65c2271
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/AddressBookRoot.php
@@ -0,0 +1,80 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAVACL;
+
+/**
+ * AddressBook rootnode
+ *
+ * This object lists a collection of users, which can contain addressbooks.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AddressBookRoot extends DAVACL\AbstractPrincipalCollection {
+
+    /**
+     * Principal Backend
+     *
+     * @var OldSabre\DAVACL\PrincipalBackend\BackendInteface
+     */
+    protected $principalBackend;
+
+    /**
+     * CardDAV backend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $carddavBackend;
+
+    /**
+     * Constructor
+     *
+     * This constructor needs both a principal and a carddav backend.
+     *
+     * By default this class will show a list of addressbook collections for
+     * principals in the 'principals' collection. If your main principals are
+     * actually located in a different path, use the $principalPrefix argument
+     * to override this.
+     *
+     * @param DAVACL\PrincipalBackend\BackendInterface $principalBackend
+     * @param Backend\BackendInterface $carddavBackend
+     * @param string $principalPrefix
+     */
+    public function __construct(DAVACL\PrincipalBackend\BackendInterface $principalBackend,Backend\BackendInterface $carddavBackend, $principalPrefix = 'principals') {
+
+        $this->carddavBackend = $carddavBackend;
+        parent::__construct($principalBackend, $principalPrefix);
+
+    }
+
+    /**
+     * Returns the name of the node
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return Plugin::ADDRESSBOOK_ROOT;
+
+    }
+
+    /**
+     * This method returns a node for a principal.
+     *
+     * The passed array contains principal information, and is guaranteed to
+     * at least contain a uri item. Other properties may or may not be
+     * supplied by the authentication backend.
+     *
+     * @param array $principal
+     * @return \OldSabre\DAV\INode
+     */
+    public function getChildForPrincipal(array $principal) {
+
+        return new UserAddressBooks($this->carddavBackend, $principal['uri']);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/AbstractBackend.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/AbstractBackend.php
new file mode 100644
index 0000000..6b90e0e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/AbstractBackend.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace OldSabre\CardDAV\Backend;
+
+/**
+ * CardDAV abstract Backend
+ *
+ * This class serves as a base-class for addressbook backends
+ *
+ * This class doesn't do much, but it was added for consistency.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractBackend implements BackendInterface {
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/BackendInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/BackendInterface.php
new file mode 100644
index 0000000..9f9e1fa
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/BackendInterface.php
@@ -0,0 +1,166 @@
+<?php
+
+namespace OldSabre\CardDAV\Backend;
+
+/**
+ * CardDAV Backend Interface
+ *
+ * Any CardDAV backend must implement this interface.
+ *
+ * Note that there are references to 'addressBookId' scattered throughout the
+ * class. The value of the addressBookId is completely up to you, it can be any
+ * arbitrary value you can use as an unique identifier.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface BackendInterface {
+
+    /**
+     * Returns the list of addressbooks for a specific user.
+     *
+     * Every addressbook should have the following properties:
+     *   id - an arbitrary unique id
+     *   uri - the 'basename' part of the url
+     *   principaluri - Same as the passed parameter
+     *
+     * Any additional clark-notation property may be passed besides this. Some
+     * common ones are :
+     *   {DAV:}displayname
+     *   {urn:ietf:params:xml:ns:carddav}addressbook-description
+     *   {http://calendarserver.org/ns/}getctag
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getAddressBooksForUser($principalUri);
+
+    /**
+     * Updates an addressbook's properties
+     *
+     * See OldSabre\DAV\IProperties for a description of the mutations array, as
+     * well as the return value.
+     *
+     * @param mixed $addressBookId
+     * @param array $mutations
+     * @see OldSabre\DAV\IProperties::updateProperties
+     * @return bool|array
+     */
+    public function updateAddressBook($addressBookId, array $mutations);
+
+    /**
+     * Creates a new address book
+     *
+     * @param string $principalUri
+     * @param string $url Just the 'basename' of the url.
+     * @param array $properties
+     * @return void
+     */
+    public function createAddressBook($principalUri, $url, array $properties);
+
+    /**
+     * Deletes an entire addressbook and all its contents
+     *
+     * @param mixed $addressBookId
+     * @return void
+     */
+    public function deleteAddressBook($addressBookId);
+
+    /**
+     * Returns all cards for a specific addressbook id.
+     *
+     * This method should return the following properties for each card:
+     *   * carddata - raw vcard data
+     *   * uri - Some unique url
+     *   * lastmodified - A unix timestamp
+     *
+     * It's recommended to also return the following properties:
+     *   * etag - A unique etag. This must change every time the card changes.
+     *   * size - The size of the card in bytes.
+     *
+     * If these last two properties are provided, less time will be spent
+     * calculating them. If they are specified, you can also ommit carddata.
+     * This may speed up certain requests, especially with large cards.
+     *
+     * @param mixed $addressbookId
+     * @return array
+     */
+    public function getCards($addressbookId);
+
+    /**
+     * Returns a specfic card.
+     *
+     * The same set of properties must be returned as with getCards. The only
+     * exception is that 'carddata' is absolutely required.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @return array
+     */
+    public function getCard($addressBookId, $cardUri);
+
+    /**
+     * Creates a new card.
+     *
+     * The addressbook id will be passed as the first argument. This is the
+     * same id as it is returned from the getAddressbooksForUser method.
+     *
+     * The cardUri is a base uri, and doesn't include the full path. The
+     * cardData argument is the vcard body, and is passed as a string.
+     *
+     * It is possible to return an ETag from this method. This ETag is for the
+     * newly created resource, and must be enclosed with double quotes (that
+     * is, the string itself must contain the double quotes).
+     *
+     * You should only return the ETag if you store the carddata as-is. If a
+     * subsequent GET request on the same card does not have the same body,
+     * byte-by-byte and you did return an ETag here, clients tend to get
+     * confused.
+     *
+     * If you don't return an ETag, you can just return null.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @param string $cardData
+     * @return string|null
+     */
+    public function createCard($addressBookId, $cardUri, $cardData);
+
+    /**
+     * Updates a card.
+     *
+     * The addressbook id will be passed as the first argument. This is the
+     * same id as it is returned from the getAddressbooksForUser method.
+     *
+     * The cardUri is a base uri, and doesn't include the full path. The
+     * cardData argument is the vcard body, and is passed as a string.
+     *
+     * It is possible to return an ETag from this method. This ETag should
+     * match that of the updated resource, and must be enclosed with double
+     * quotes (that is: the string itself must contain the actual quotes).
+     *
+     * You should only return the ETag if you store the carddata as-is. If a
+     * subsequent GET request on the same card does not have the same body,
+     * byte-by-byte and you did return an ETag here, clients tend to get
+     * confused.
+     *
+     * If you don't return an ETag, you can just return null.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @param string $cardData
+     * @return string|null
+     */
+    public function updateCard($addressBookId, $cardUri, $cardData);
+
+    /**
+     * Deletes a card
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @return bool
+     */
+    public function deleteCard($addressBookId, $cardUri);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/PDO.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/PDO.php
new file mode 100644
index 0000000..e20b980
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Backend/PDO.php
@@ -0,0 +1,333 @@
+<?php
+
+namespace OldSabre\CardDAV\Backend;
+
+use OldSabre\CardDAV;
+use OldSabre\DAV;
+
+/**
+ * PDO CardDAV backend
+ *
+ * This CardDAV backend uses PDO to store addressbooks
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PDO extends AbstractBackend {
+
+    /**
+     * PDO connection
+     *
+     * @var PDO
+     */
+    protected $pdo;
+
+    /**
+     * The PDO table name used to store addressbooks
+     */
+    protected $addressBooksTableName;
+
+    /**
+     * The PDO table name used to store cards
+     */
+    protected $cardsTableName;
+
+    /**
+     * Sets up the object
+     *
+     * @param \PDO $pdo
+     * @param string $addressBooksTableName
+     * @param string $cardsTableName
+     */
+    public function __construct(\PDO $pdo, $addressBooksTableName = 'addressbooks', $cardsTableName = 'cards') {
+
+        $this->pdo = $pdo;
+        $this->addressBooksTableName = $addressBooksTableName;
+        $this->cardsTableName = $cardsTableName;
+
+    }
+
+    /**
+     * Returns the list of addressbooks for a specific user.
+     *
+     * @param string $principalUri
+     * @return array
+     */
+    public function getAddressBooksForUser($principalUri) {
+
+        $stmt = $this->pdo->prepare('SELECT id, uri, displayname, principaluri, description, ctag FROM '.$this->addressBooksTableName.' WHERE principaluri = ?');
+        $stmt->execute(array($principalUri));
+
+        $addressBooks = array();
+
+        foreach($stmt->fetchAll() as $row) {
+
+            $addressBooks[] = array(
+                'id'  => $row['id'],
+                'uri' => $row['uri'],
+                'principaluri' => $row['principaluri'],
+                '{DAV:}displayname' => $row['displayname'],
+                '{' . CardDAV\Plugin::NS_CARDDAV . '}addressbook-description' => $row['description'],
+                '{http://calendarserver.org/ns/}getctag' => $row['ctag'],
+                '{' . CardDAV\Plugin::NS_CARDDAV . '}supported-address-data' =>
+                    new CardDAV\Property\SupportedAddressData(),
+            );
+
+        }
+
+        return $addressBooks;
+
+    }
+
+
+    /**
+     * Updates an addressbook's properties
+     *
+     * See OldSabre\DAV\IProperties for a description of the mutations array, as
+     * well as the return value.
+     *
+     * @param mixed $addressBookId
+     * @param array $mutations
+     * @see OldSabre\DAV\IProperties::updateProperties
+     * @return bool|array
+     */
+    public function updateAddressBook($addressBookId, array $mutations) {
+
+        $updates = array();
+
+        foreach($mutations as $property=>$newValue) {
+
+            switch($property) {
+                case '{DAV:}displayname' :
+                    $updates['displayname'] = $newValue;
+                    break;
+                case '{' . CardDAV\Plugin::NS_CARDDAV . '}addressbook-description' :
+                    $updates['description'] = $newValue;
+                    break;
+                default :
+                    // If any unsupported values were being updated, we must
+                    // let the entire request fail.
+                    return false;
+            }
+
+        }
+
+        // No values are being updated?
+        if (!$updates) {
+            return false;
+        }
+
+        $query = 'UPDATE ' . $this->addressBooksTableName . ' SET ctag = ctag + 1 ';
+        foreach($updates as $key=>$value) {
+            $query.=', `' . $key . '` = :' . $key . ' ';
+        }
+        $query.=' WHERE id = :addressbookid';
+
+        $stmt = $this->pdo->prepare($query);
+        $updates['addressbookid'] = $addressBookId;
+
+        $stmt->execute($updates);
+
+        return true;
+
+    }
+
+    /**
+     * Creates a new address book
+     *
+     * @param string $principalUri
+     * @param string $url Just the 'basename' of the url.
+     * @param array $properties
+     * @return void
+     */
+    public function createAddressBook($principalUri, $url, array $properties) {
+
+        $values = array(
+            'displayname' => null,
+            'description' => null,
+            'principaluri' => $principalUri,
+            'uri' => $url,
+        );
+
+        foreach($properties as $property=>$newValue) {
+
+            switch($property) {
+                case '{DAV:}displayname' :
+                    $values['displayname'] = $newValue;
+                    break;
+                case '{' . CardDAV\Plugin::NS_CARDDAV . '}addressbook-description' :
+                    $values['description'] = $newValue;
+                    break;
+                default :
+                    throw new DAV\Exception\BadRequest('Unknown property: ' . $property);
+            }
+
+        }
+
+        $query = 'INSERT INTO ' . $this->addressBooksTableName . ' (uri, displayname, description, principaluri, ctag) VALUES (:uri, :displayname, :description, :principaluri, 1)';
+        $stmt = $this->pdo->prepare($query);
+        $stmt->execute($values);
+
+    }
+
+    /**
+     * Deletes an entire addressbook and all its contents
+     *
+     * @param int $addressBookId
+     * @return void
+     */
+    public function deleteAddressBook($addressBookId) {
+
+        $stmt = $this->pdo->prepare('DELETE FROM ' . $this->cardsTableName . ' WHERE addressbookid = ?');
+        $stmt->execute(array($addressBookId));
+
+        $stmt = $this->pdo->prepare('DELETE FROM ' . $this->addressBooksTableName . ' WHERE id = ?');
+        $stmt->execute(array($addressBookId));
+
+    }
+
+    /**
+     * Returns all cards for a specific addressbook id.
+     *
+     * This method should return the following properties for each card:
+     *   * carddata - raw vcard data
+     *   * uri - Some unique url
+     *   * lastmodified - A unix timestamp
+     *
+     * It's recommended to also return the following properties:
+     *   * etag - A unique etag. This must change every time the card changes.
+     *   * size - The size of the card in bytes.
+     *
+     * If these last two properties are provided, less time will be spent
+     * calculating them. If they are specified, you can also ommit carddata.
+     * This may speed up certain requests, especially with large cards.
+     *
+     * @param mixed $addressbookId
+     * @return array
+     */
+    public function getCards($addressbookId) {
+
+        $stmt = $this->pdo->prepare('SELECT id, carddata, uri, lastmodified FROM ' . $this->cardsTableName . ' WHERE addressbookid = ?');
+        $stmt->execute(array($addressbookId));
+
+        return $stmt->fetchAll(\PDO::FETCH_ASSOC);
+
+
+    }
+
+    /**
+     * Returns a specfic card.
+     *
+     * The same set of properties must be returned as with getCards. The only
+     * exception is that 'carddata' is absolutely required.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @return array
+     */
+    public function getCard($addressBookId, $cardUri) {
+
+        $stmt = $this->pdo->prepare('SELECT id, carddata, uri, lastmodified FROM ' . $this->cardsTableName . ' WHERE addressbookid = ? AND uri = ? LIMIT 1');
+        $stmt->execute(array($addressBookId, $cardUri));
+
+        $result = $stmt->fetchAll(\PDO::FETCH_ASSOC);
+
+        return (count($result)>0?$result[0]:false);
+
+    }
+
+    /**
+     * Creates a new card.
+     *
+     * The addressbook id will be passed as the first argument. This is the
+     * same id as it is returned from the getAddressbooksForUser method.
+     *
+     * The cardUri is a base uri, and doesn't include the full path. The
+     * cardData argument is the vcard body, and is passed as a string.
+     *
+     * It is possible to return an ETag from this method. This ETag is for the
+     * newly created resource, and must be enclosed with double quotes (that
+     * is, the string itself must contain the double quotes).
+     *
+     * You should only return the ETag if you store the carddata as-is. If a
+     * subsequent GET request on the same card does not have the same body,
+     * byte-by-byte and you did return an ETag here, clients tend to get
+     * confused.
+     *
+     * If you don't return an ETag, you can just return null.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @param string $cardData
+     * @return string|null
+     */
+    public function createCard($addressBookId, $cardUri, $cardData) {
+
+        $stmt = $this->pdo->prepare('INSERT INTO ' . $this->cardsTableName . ' (carddata, uri, lastmodified, addressbookid) VALUES (?, ?, ?, ?)');
+
+        $result = $stmt->execute(array($cardData, $cardUri, time(), $addressBookId));
+
+        $stmt2 = $this->pdo->prepare('UPDATE ' . $this->addressBooksTableName . ' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt2->execute(array($addressBookId));
+
+        return '"' . md5($cardData) . '"';
+
+    }
+
+    /**
+     * Updates a card.
+     *
+     * The addressbook id will be passed as the first argument. This is the
+     * same id as it is returned from the getAddressbooksForUser method.
+     *
+     * The cardUri is a base uri, and doesn't include the full path. The
+     * cardData argument is the vcard body, and is passed as a string.
+     *
+     * It is possible to return an ETag from this method. This ETag should
+     * match that of the updated resource, and must be enclosed with double
+     * quotes (that is: the string itself must contain the actual quotes).
+     *
+     * You should only return the ETag if you store the carddata as-is. If a
+     * subsequent GET request on the same card does not have the same body,
+     * byte-by-byte and you did return an ETag here, clients tend to get
+     * confused.
+     *
+     * If you don't return an ETag, you can just return null.
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @param string $cardData
+     * @return string|null
+     */
+    public function updateCard($addressBookId, $cardUri, $cardData) {
+
+        $stmt = $this->pdo->prepare('UPDATE ' . $this->cardsTableName . ' SET carddata = ?, lastmodified = ? WHERE uri = ? AND addressbookid =?');
+        $stmt->execute(array($cardData, time(), $cardUri, $addressBookId));
+
+        $stmt2 = $this->pdo->prepare('UPDATE ' . $this->addressBooksTableName . ' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt2->execute(array($addressBookId));
+
+        return '"' . md5($cardData) . '"';
+
+    }
+
+    /**
+     * Deletes a card
+     *
+     * @param mixed $addressBookId
+     * @param string $cardUri
+     * @return bool
+     */
+    public function deleteCard($addressBookId, $cardUri) {
+
+        $stmt = $this->pdo->prepare('DELETE FROM ' . $this->cardsTableName . ' WHERE addressbookid = ? AND uri = ?');
+        $stmt->execute(array($addressBookId, $cardUri));
+
+        $stmt2 = $this->pdo->prepare('UPDATE ' . $this->addressBooksTableName . ' SET ctag = ctag + 1 WHERE id = ?');
+        $stmt2->execute(array($addressBookId));
+
+        return $stmt->rowCount()===1;
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Card.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Card.php
new file mode 100644
index 0000000..08ab828
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Card.php
@@ -0,0 +1,260 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAVACL;
+use OldSabre\DAV;
+
+
+/**
+ * The Card object represents a single Card from an addressbook
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Card extends DAV\File implements ICard, DAVACL\IACL {
+
+    /**
+     * CardDAV backend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $carddavBackend;
+
+    /**
+     * Array with information about this Card
+     *
+     * @var array
+     */
+    protected $cardData;
+
+    /**
+     * Array with information about the containing addressbook
+     *
+     * @var array
+     */
+    protected $addressBookInfo;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $carddavBackend
+     * @param array $addressBookInfo
+     * @param array $cardData
+     */
+    public function __construct(Backend\BackendInterface $carddavBackend,array $addressBookInfo,array $cardData) {
+
+        $this->carddavBackend = $carddavBackend;
+        $this->addressBookInfo = $addressBookInfo;
+        $this->cardData = $cardData;
+
+    }
+
+    /**
+     * Returns the uri for this object
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->cardData['uri'];
+
+    }
+
+    /**
+     * Returns the VCard-formatted object
+     *
+     * @return string
+     */
+    public function get() {
+
+        // Pre-populating 'carddata' is optional. If we don't yet have it
+        // already, we fetch it from the backend.
+        if (!isset($this->cardData['carddata'])) {
+            $this->cardData = $this->carddavBackend->getCard($this->addressBookInfo['id'], $this->cardData['uri']);
+        }
+        return $this->cardData['carddata'];
+
+    }
+
+    /**
+     * Updates the VCard-formatted object
+     *
+     * @param string $cardData
+     * @return string|null
+     */
+    public function put($cardData) {
+
+        if (is_resource($cardData))
+            $cardData = stream_get_contents($cardData);
+
+        // Converting to UTF-8, if needed
+        $cardData = DAV\StringUtil::ensureUTF8($cardData);
+
+        $etag = $this->carddavBackend->updateCard($this->addressBookInfo['id'],$this->cardData['uri'],$cardData);
+        $this->cardData['carddata'] = $cardData;
+        $this->cardData['etag'] = $etag;
+
+        return $etag;
+
+    }
+
+    /**
+     * Deletes the card
+     *
+     * @return void
+     */
+    public function delete() {
+
+        $this->carddavBackend->deleteCard($this->addressBookInfo['id'],$this->cardData['uri']);
+
+    }
+
+    /**
+     * Returns the mime content-type
+     *
+     * @return string
+     */
+    public function getContentType() {
+
+        return 'text/x-vcard; charset=utf-8';
+
+    }
+
+    /**
+     * Returns an ETag for this object
+     *
+     * @return string
+     */
+    public function getETag() {
+
+        if (isset($this->cardData['etag'])) {
+            return $this->cardData['etag'];
+        } else {
+            $data = $this->get();
+            if (is_string($data)) {
+                return '"' . md5($data) . '"';
+            } else {
+                // We refuse to calculate the md5 if it's a stream.
+                return null;
+            }
+        }
+
+    }
+
+    /**
+     * Returns the last modification date as a unix timestamp
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return isset($this->cardData['lastmodified'])?$this->cardData['lastmodified']:null;
+
+    }
+
+    /**
+     * Returns the size of this object in bytes
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        if (array_key_exists('size', $this->cardData)) {
+            return $this->cardData['size'];
+        } else {
+            return strlen($this->get());
+        }
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->addressBookInfo['principaluri'];
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->addressBookInfo['principaluri'],
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->addressBookInfo['principaluri'],
+                'protected' => true,
+            ),
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IAddressBook.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IAddressBook.php
new file mode 100644
index 0000000..9670c85
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IAddressBook.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+
+/**
+ * AddressBook interface
+ *
+ * Implement this interface to allow a node to be recognized as an addressbook.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IAddressBook extends DAV\ICollection {
+
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/ICard.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/ICard.php
new file mode 100644
index 0000000..9d8945f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/ICard.php
@@ -0,0 +1,20 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+
+/**
+ * Card interface
+ *
+ * Extend the ICard interface to allow your custom nodes to be picked up as
+ * 'Cards'.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ICard extends DAV\IFile {
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IDirectory.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IDirectory.php
new file mode 100644
index 0000000..7d3a3bd
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/IDirectory.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+/**
+ * IDirectory interface
+ *
+ * Implement this interface to have an addressbook marked as a 'directory'. A
+ * directory is an (often) global addressbook.
+ *
+ * A full description can be found in the IETF draft:
+ *   - draft-daboo-carddav-directory-gateway
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IDirectory extends IAddressBook {
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Plugin.php
new file mode 100644
index 0000000..fa3077b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Plugin.php
@@ -0,0 +1,706 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+use OldSabre\VObject;
+
+/**
+ * CardDAV plugin
+ *
+ * The CardDAV plugin adds CardDAV functionality to the WebDAV server
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * Url to the addressbooks
+     */
+    const ADDRESSBOOK_ROOT = 'addressbooks';
+
+    /**
+     * xml namespace for CardDAV elements
+     */
+    const NS_CARDDAV = 'urn:ietf:params:xml:ns:carddav';
+
+    /**
+     * Add urls to this property to have them automatically exposed as
+     * 'directories' to the user.
+     *
+     * @var array
+     */
+    public $directories = array();
+
+    /**
+     * Server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        /* Events */
+        $server->subscribeEvent('beforeGetProperties', array($this, 'beforeGetProperties'));
+        $server->subscribeEvent('afterGetProperties',  array($this, 'afterGetProperties'));
+        $server->subscribeEvent('updateProperties', array($this, 'updateProperties'));
+        $server->subscribeEvent('report', array($this,'report'));
+        $server->subscribeEvent('onHTMLActionsPanel', array($this,'htmlActionsPanel'));
+        $server->subscribeEvent('onBrowserPostAction', array($this,'browserPostAction'));
+        $server->subscribeEvent('beforeWriteContent', array($this, 'beforeWriteContent'));
+        $server->subscribeEvent('beforeCreateFile', array($this, 'beforeCreateFile'));
+
+        /* Namespaces */
+        $server->xmlNamespaces[self::NS_CARDDAV] = 'card';
+
+        /* Mapping Interfaces to {DAV:}resourcetype values */
+        $server->resourceTypeMapping['OldSabre\\CardDAV\\IAddressBook'] = '{' . self::NS_CARDDAV . '}addressbook';
+        $server->resourceTypeMapping['OldSabre\\CardDAV\\IDirectory'] = '{' . self::NS_CARDDAV . '}directory';
+
+        /* Adding properties that may never be changed */
+        $server->protectedProperties[] = '{' . self::NS_CARDDAV . '}supported-address-data';
+        $server->protectedProperties[] = '{' . self::NS_CARDDAV . '}max-resource-size';
+        $server->protectedProperties[] = '{' . self::NS_CARDDAV . '}addressbook-home-set';
+        $server->protectedProperties[] = '{' . self::NS_CARDDAV . '}supported-collation-set';
+
+        $server->propertyMap['{http://calendarserver.org/ns/}me-card'] = 'OldSabre\\DAV\\Property\\Href';
+
+        $this->server = $server;
+
+    }
+
+    /**
+     * Returns a list of supported features.
+     *
+     * This is used in the DAV: header in the OPTIONS and PROPFIND requests.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array('addressbook');
+
+    }
+
+    /**
+     * Returns a list of reports this plugin supports.
+     *
+     * This will be used in the {DAV:}supported-report-set property.
+     * Note that you still need to subscribe to the 'report' event to actually
+     * implement them
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getSupportedReportSet($uri) {
+
+        $node = $this->server->tree->getNodeForPath($uri);
+        if ($node instanceof IAddressBook || $node instanceof ICard) {
+            return array(
+                 '{' . self::NS_CARDDAV . '}addressbook-multiget',
+                 '{' . self::NS_CARDDAV . '}addressbook-query',
+            );
+        }
+        return array();
+
+    }
+
+
+    /**
+     * Adds all CardDAV-specific properties
+     *
+     * @param string $path
+     * @param DAV\INode $node
+     * @param array $requestedProperties
+     * @param array $returnedProperties
+     * @return void
+     */
+    public function beforeGetProperties($path, DAV\INode $node, array &$requestedProperties, array &$returnedProperties) {
+
+        if ($node instanceof DAVACL\IPrincipal) {
+
+            // calendar-home-set property
+            $addHome = '{' . self::NS_CARDDAV . '}addressbook-home-set';
+            if (in_array($addHome,$requestedProperties)) {
+                $principalId = $node->getName();
+                $addressbookHomePath = self::ADDRESSBOOK_ROOT . '/' . $principalId . '/';
+                unset($requestedProperties[array_search($addHome, $requestedProperties)]);
+                $returnedProperties[200][$addHome] = new DAV\Property\Href($addressbookHomePath);
+            }
+
+            $directories = '{' . self::NS_CARDDAV . '}directory-gateway';
+            if ($this->directories && in_array($directories, $requestedProperties)) {
+                unset($requestedProperties[array_search($directories, $requestedProperties)]);
+                $returnedProperties[200][$directories] = new DAV\Property\HrefList($this->directories);
+            }
+
+        }
+
+        if ($node instanceof ICard) {
+
+            // The address-data property is not supposed to be a 'real'
+            // property, but in large chunks of the spec it does act as such.
+            // Therefore we simply expose it as a property.
+            $addressDataProp = '{' . self::NS_CARDDAV . '}address-data';
+            if (in_array($addressDataProp, $requestedProperties)) {
+                unset($requestedProperties[$addressDataProp]);
+                $val = $node->get();
+                if (is_resource($val))
+                    $val = stream_get_contents($val);
+
+                $returnedProperties[200][$addressDataProp] = $val;
+
+            }
+        }
+
+        if ($node instanceof UserAddressBooks) {
+
+            $meCardProp = '{http://calendarserver.org/ns/}me-card';
+            if (in_array($meCardProp, $requestedProperties)) {
+
+                $props = $this->server->getProperties($node->getOwner(), array('{http://sabredav.org/ns}vcard-url'));
+                if (isset($props['{http://sabredav.org/ns}vcard-url'])) {
+
+                    $returnedProperties[200][$meCardProp] = new DAV\Property\Href(
+                        $props['{http://sabredav.org/ns}vcard-url']
+                    );
+                    $pos = array_search($meCardProp, $requestedProperties);
+                    unset($requestedProperties[$pos]);
+
+                }
+
+            }
+
+        }
+
+    }
+
+    /**
+     * This event is triggered when a PROPPATCH method is executed
+     *
+     * @param array $mutations
+     * @param array $result
+     * @param DAV\INode $node
+     * @return bool
+     */
+    public function updateProperties(&$mutations, &$result, DAV\INode $node) {
+
+        if (!$node instanceof UserAddressBooks) {
+            return true;
+        }
+
+        $meCard = '{http://calendarserver.org/ns/}me-card';
+
+        // The only property we care about
+        if (!isset($mutations[$meCard]))
+            return true;
+
+        $value = $mutations[$meCard];
+        unset($mutations[$meCard]);
+
+        if ($value instanceof DAV\Property\IHref) {
+            $value = $value->getHref();
+            $value = $this->server->calculateUri($value);
+        } elseif (!is_null($value)) {
+            $result[400][$meCard] = null;
+            return false;
+        }
+
+        $innerResult = $this->server->updateProperties(
+            $node->getOwner(),
+            array(
+                '{http://sabredav.org/ns}vcard-url' => $value,
+            )
+        );
+
+        $closureResult = false;
+        foreach($innerResult as $status => $props) {
+            if (is_array($props) && array_key_exists('{http://sabredav.org/ns}vcard-url', $props)) {
+                $result[$status][$meCard] = null;
+                $closureResult = ($status>=200 && $status<300);
+            }
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * This functions handles REPORT requests specific to CardDAV
+     *
+     * @param string $reportName
+     * @param \DOMNode $dom
+     * @return bool
+     */
+    public function report($reportName,$dom) {
+
+        switch($reportName) {
+            case '{'.self::NS_CARDDAV.'}addressbook-multiget' :
+                $this->addressbookMultiGetReport($dom);
+                return false;
+            case '{'.self::NS_CARDDAV.'}addressbook-query' :
+                $this->addressBookQueryReport($dom);
+                return false;
+            default :
+                return;
+
+        }
+
+
+    }
+
+    /**
+     * This function handles the addressbook-multiget REPORT.
+     *
+     * This report is used by the client to fetch the content of a series
+     * of urls. Effectively avoiding a lot of redundant requests.
+     *
+     * @param \DOMNode $dom
+     * @return void
+     */
+    public function addressbookMultiGetReport($dom) {
+
+        $properties = array_keys(DAV\XMLUtil::parseProperties($dom->firstChild));
+
+        $hrefElems = $dom->getElementsByTagNameNS('urn:DAV','href');
+        $propertyList = array();
+
+        foreach($hrefElems as $elem) {
+
+            $uri = $this->server->calculateUri($elem->nodeValue);
+            list($propertyList[]) = $this->server->getPropertiesForPath($uri,$properties);
+
+        }
+
+        $prefer = $this->server->getHTTPPRefer();
+
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Vary','Brief,Prefer');
+        $this->server->httpResponse->sendBody($this->server->generateMultiStatus($propertyList, $prefer['return-minimal']));
+
+    }
+
+    /**
+     * This method is triggered before a file gets updated with new content.
+     *
+     * This plugin uses this method to ensure that Card nodes receive valid
+     * vcard data.
+     *
+     * @param string $path
+     * @param DAV\IFile $node
+     * @param resource $data
+     * @return void
+     */
+    public function beforeWriteContent($path, DAV\IFile $node, &$data) {
+
+        if (!$node instanceof ICard)
+            return;
+
+        $this->validateVCard($data);
+
+    }
+
+    /**
+     * This method is triggered before a new file is created.
+     *
+     * This plugin uses this method to ensure that Card nodes receive valid
+     * vcard data.
+     *
+     * @param string $path
+     * @param resource $data
+     * @param DAV\ICollection $parentNode
+     * @return void
+     */
+    public function beforeCreateFile($path, &$data, DAV\ICollection $parentNode) {
+
+        if (!$parentNode instanceof IAddressBook)
+            return;
+
+        $this->validateVCard($data);
+
+    }
+
+    /**
+     * Checks if the submitted iCalendar data is in fact, valid.
+     *
+     * An exception is thrown if it's not.
+     *
+     * @param resource|string $data
+     * @return void
+     */
+    protected function validateVCard(&$data) {
+
+        // If it's a stream, we convert it to a string first.
+        if (is_resource($data)) {
+            $data = stream_get_contents($data);
+        }
+
+        // Converting the data to unicode, if needed.
+        $data = DAV\StringUtil::ensureUTF8($data);
+
+        try {
+
+            $vobj = VObject\Reader::read($data);
+
+        } catch (VObject\ParseException $e) {
+
+            throw new DAV\Exception\UnsupportedMediaType('This resource only supports valid vcard data. Parse error: ' . $e->getMessage());
+
+        }
+
+        if ($vobj->name !== 'VCARD') {
+            throw new DAV\Exception\UnsupportedMediaType('This collection can only support vcard objects.');
+        }
+
+        if (!isset($vobj->UID)) {
+            // No UID in vcards is invalid, but we'll just add it in anyway.
+            $vobj->add('UID', DAV\UUIDUtil::getUUID());
+            $data = $vobj->serialize();
+        }
+
+    }
+
+
+    /**
+     * This function handles the addressbook-query REPORT
+     *
+     * This report is used by the client to filter an addressbook based on a
+     * complex query.
+     *
+     * @param \DOMNode $dom
+     * @return void
+     */
+    protected function addressbookQueryReport($dom) {
+
+        $query = new AddressBookQueryParser($dom);
+        $query->parse();
+
+        $depth = $this->server->getHTTPDepth(0);
+
+        if ($depth==0) {
+            $candidateNodes = array(
+                $this->server->tree->getNodeForPath($this->server->getRequestUri())
+            );
+        } else {
+            $candidateNodes = $this->server->tree->getChildren($this->server->getRequestUri());
+        }
+
+        $validNodes = array();
+        foreach($candidateNodes as $node) {
+
+            if (!$node instanceof ICard)
+                continue;
+
+            $blob = $node->get();
+            if (is_resource($blob)) {
+                $blob = stream_get_contents($blob);
+            }
+
+            if (!$this->validateFilters($blob, $query->filters, $query->test)) {
+                continue;
+            }
+
+            $validNodes[] = $node;
+
+            if ($query->limit && $query->limit <= count($validNodes)) {
+                // We hit the maximum number of items, we can stop now.
+                break;
+            }
+
+        }
+
+        $result = array();
+        foreach($validNodes as $validNode) {
+
+            if ($depth==0) {
+                $href = $this->server->getRequestUri();
+            } else {
+                $href = $this->server->getRequestUri() . '/' . $validNode->getName();
+            }
+
+            list($result[]) = $this->server->getPropertiesForPath($href, $query->requestedProperties, 0);
+
+        }
+
+        $prefer = $this->server->getHTTPPRefer();
+
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Vary','Brief,Prefer');
+        $this->server->httpResponse->sendBody($this->server->generateMultiStatus($result, $prefer['return-minimal']));
+
+    }
+
+    /**
+     * Validates if a vcard makes it throught a list of filters.
+     *
+     * @param string $vcardData
+     * @param array $filters
+     * @param string $test anyof or allof (which means OR or AND)
+     * @return bool
+     */
+    public function validateFilters($vcardData, array $filters, $test) {
+
+        $vcard = VObject\Reader::read($vcardData);
+
+        if (!$filters) return true;
+
+        foreach($filters as $filter) {
+
+            $isDefined = isset($vcard->{$filter['name']});
+            if ($filter['is-not-defined']) {
+                if ($isDefined) {
+                    $success = false;
+                } else {
+                    $success = true;
+                }
+            } elseif ((!$filter['param-filters'] && !$filter['text-matches']) || !$isDefined) {
+
+                // We only need to check for existence
+                $success = $isDefined;
+
+            } else {
+
+                $vProperties = $vcard->select($filter['name']);
+
+                $results = array();
+                if ($filter['param-filters']) {
+                    $results[] = $this->validateParamFilters($vProperties, $filter['param-filters'], $filter['test']);
+                }
+                if ($filter['text-matches']) {
+                    $texts = array();
+                    foreach($vProperties as $vProperty)
+                        $texts[] = $vProperty->getValue();
+
+                    $results[] = $this->validateTextMatches($texts, $filter['text-matches'], $filter['test']);
+                }
+
+                if (count($results)===1) {
+                    $success = $results[0];
+                } else {
+                    if ($filter['test'] === 'anyof') {
+                        $success = $results[0] || $results[1];
+                    } else {
+                        $success = $results[0] && $results[1];
+                    }
+                }
+
+            } // else
+
+            // There are two conditions where we can already determine whether
+            // or not this filter succeeds.
+            if ($test==='anyof' && $success) {
+                return true;
+            }
+            if ($test==='allof' && !$success) {
+                return false;
+            }
+
+        } // foreach
+
+        // If we got all the way here, it means we haven't been able to
+        // determine early if the test failed or not.
+        //
+        // This implies for 'anyof' that the test failed, and for 'allof' that
+        // we succeeded. Sounds weird, but makes sense.
+        return $test==='allof';
+
+    }
+
+    /**
+     * Validates if a param-filter can be applied to a specific property.
+     *
+     * @todo currently we're only validating the first parameter of the passed
+     *       property. Any subsequence parameters with the same name are
+     *       ignored.
+     * @param array $vProperties
+     * @param array $filters
+     * @param string $test
+     * @return bool
+     */
+    protected function validateParamFilters(array $vProperties, array $filters, $test) {
+
+        foreach($filters as $filter) {
+
+            $isDefined = false;
+            foreach($vProperties as $vProperty) {
+                $isDefined = isset($vProperty[$filter['name']]);
+                if ($isDefined) break;
+            }
+
+            if ($filter['is-not-defined']) {
+                if ($isDefined) {
+                    $success = false;
+                } else {
+                    $success = true;
+                }
+
+            // If there's no text-match, we can just check for existence
+            } elseif (!$filter['text-match'] || !$isDefined) {
+
+                $success = $isDefined;
+
+            } else {
+
+                $success = false;
+                foreach($vProperties as $vProperty) {
+                    // If we got all the way here, we'll need to validate the
+                    // text-match filter.
+                    $success = DAV\StringUtil::textMatch($vProperty[$filter['name']]->getValue(), $filter['text-match']['value'], $filter['text-match']['collation'], $filter['text-match']['match-type']);
+                    if ($success) break;
+                }
+                if ($filter['text-match']['negate-condition']) {
+                    $success = !$success;
+                }
+
+            } // else
+
+            // There are two conditions where we can already determine whether
+            // or not this filter succeeds.
+            if ($test==='anyof' && $success) {
+                return true;
+            }
+            if ($test==='allof' && !$success) {
+                return false;
+            }
+
+        }
+
+        // If we got all the way here, it means we haven't been able to
+        // determine early if the test failed or not.
+        //
+        // This implies for 'anyof' that the test failed, and for 'allof' that
+        // we succeeded. Sounds weird, but makes sense.
+        return $test==='allof';
+
+    }
+
+    /**
+     * Validates if a text-filter can be applied to a specific property.
+     *
+     * @param array $texts
+     * @param array $filters
+     * @param string $test
+     * @return bool
+     */
+    protected function validateTextMatches(array $texts, array $filters, $test) {
+
+        foreach($filters as $filter) {
+
+            $success = false;
+            foreach($texts as $haystack) {
+                $success = DAV\StringUtil::textMatch($haystack, $filter['value'], $filter['collation'], $filter['match-type']);
+
+                // Breaking on the first match
+                if ($success) break;
+            }
+            if ($filter['negate-condition']) {
+                $success = !$success;
+            }
+
+            if ($success && $test==='anyof')
+                return true;
+
+            if (!$success && $test=='allof')
+                return false;
+
+
+        }
+
+        // If we got all the way here, it means we haven't been able to
+        // determine early if the test failed or not.
+        //
+        // This implies for 'anyof' that the test failed, and for 'allof' that
+        // we succeeded. Sounds weird, but makes sense.
+        return $test==='allof';
+
+    }
+
+    /**
+     * This event is triggered after webdav-properties have been retrieved.
+     *
+     * @return bool
+     */
+    public function afterGetProperties($uri, &$properties) {
+
+        // If the request was made using the SOGO connector, we must rewrite
+        // the content-type property. By default SabreDAV will send back
+        // text/x-vcard; charset=utf-8, but for SOGO we must strip that last
+        // part.
+        if (!isset($properties[200]['{DAV:}getcontenttype']))
+            return;
+
+        if (strpos($this->server->httpRequest->getHeader('User-Agent'),'Thunderbird')===false) {
+            return;
+        }
+
+        if (strpos($properties[200]['{DAV:}getcontenttype'],'text/x-vcard')===0) {
+            $properties[200]['{DAV:}getcontenttype'] = 'text/x-vcard';
+        }
+
+    }
+
+    /**
+     * This method is used to generate HTML output for the
+     * OldSabre\DAV\Browser\Plugin. This allows us to generate an interface users
+     * can use to create new calendars.
+     *
+     * @param DAV\INode $node
+     * @param string $output
+     * @return bool
+     */
+    public function htmlActionsPanel(DAV\INode $node, &$output) {
+
+        if (!$node instanceof UserAddressBooks)
+            return;
+
+        $output.= '<tr><td colspan="2"><form method="post" action="">
+            <h3>Create new address book</h3>
+            <input type="hidden" name="sabreAction" value="mkaddressbook" />
+            <label>Name (uri):</label> <input type="text" name="name" /><br />
+            <label>Display name:</label> <input type="text" name="{DAV:}displayname" /><br />
+            <input type="submit" value="create" />
+            </form>
+            </td></tr>';
+
+        return false;
+
+    }
+
+    /**
+     * This method allows us to intercept the 'mkcalendar' sabreAction. This
+     * action enables the user to create new calendars from the browser plugin.
+     *
+     * @param string $uri
+     * @param string $action
+     * @param array $postVars
+     * @return bool
+     */
+    public function browserPostAction($uri, $action, array $postVars) {
+
+        if ($action!=='mkaddressbook')
+            return;
+
+        $resourceType = array('{DAV:}collection','{urn:ietf:params:xml:ns:carddav}addressbook');
+        $properties = array();
+        if (isset($postVars['{DAV:}displayname'])) {
+            $properties['{DAV:}displayname'] = $postVars['{DAV:}displayname'];
+        }
+        $this->server->createCollection($uri . '/' . $postVars['name'],$resourceType,$properties);
+        return false;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Property/SupportedAddressData.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Property/SupportedAddressData.php
new file mode 100644
index 0000000..c27c678
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Property/SupportedAddressData.php
@@ -0,0 +1,72 @@
+<?php
+
+namespace OldSabre\CardDAV\Property;
+
+use OldSabre\DAV;
+use OldSabre\CardDAV;
+
+/**
+ * Supported-address-data property
+ *
+ * This property is a representation of the supported-address-data property
+ * in the CardDAV namespace.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedAddressData extends DAV\Property {
+
+    /**
+     * supported versions
+     *
+     * @var array
+     */
+    protected $supportedData = array();
+
+    /**
+     * Creates the property
+     *
+     * @param array|null $supportedData
+     */
+    public function __construct(array $supportedData = null) {
+
+        if (is_null($supportedData)) {
+            $supportedData = array(
+                array('contentType' => 'text/vcard', 'version' => '3.0'),
+                // array('contentType' => 'text/vcard', 'version' => '4.0'),
+            );
+        }
+
+       $this->supportedData = $supportedData;
+
+    }
+
+    /**
+     * Serializes the property in a DOMDocument
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+
+        $prefix =
+            isset($server->xmlNamespaces[CardDAV\Plugin::NS_CARDDAV]) ?
+            $server->xmlNamespaces[CardDAV\Plugin::NS_CARDDAV] :
+            'card';
+
+        foreach($this->supportedData as $supported) {
+
+            $caldata = $doc->createElementNS(CardDAV\Plugin::NS_CARDDAV, $prefix . ':address-data-type');
+            $caldata->setAttribute('content-type',$supported['contentType']);
+            $caldata->setAttribute('version',$supported['version']);
+            $node->appendChild($caldata);
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/UserAddressBooks.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/UserAddressBooks.php
new file mode 100644
index 0000000..7f3ac6f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/UserAddressBooks.php
@@ -0,0 +1,260 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * UserAddressBooks class
+ *
+ * The UserAddressBooks collection contains a list of addressbooks associated with a user
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class UserAddressBooks extends DAV\Collection implements DAV\IExtendedCollection, DAVACL\IACL {
+
+    /**
+     * Principal uri
+     *
+     * @var array
+     */
+    protected $principalUri;
+
+    /**
+     * carddavBackend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $carddavBackend;
+
+    /**
+     * Constructor
+     *
+     * @param Backend\BackendInterface $carddavBackend
+     * @param string $principalUri
+     */
+    public function __construct(Backend\BackendInterface $carddavBackend, $principalUri) {
+
+        $this->carddavBackend = $carddavBackend;
+        $this->principalUri = $principalUri;
+
+    }
+
+    /**
+     * Returns the name of this object
+     *
+     * @return string
+     */
+    public function getName() {
+
+        list(,$name) = DAV\URLUtil::splitPath($this->principalUri);
+        return $name;
+
+    }
+
+    /**
+     * Updates the name of this object
+     *
+     * @param string $name
+     * @return void
+     */
+    public function setName($name) {
+
+        throw new DAV\Exception\MethodNotAllowed();
+
+    }
+
+    /**
+     * Deletes this object
+     *
+     * @return void
+     */
+    public function delete() {
+
+        throw new DAV\Exception\MethodNotAllowed();
+
+    }
+
+    /**
+     * Returns the last modification date
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return null;
+
+    }
+
+    /**
+     * Creates a new file under this object.
+     *
+     * This is currently not allowed
+     *
+     * @param string $filename
+     * @param resource $data
+     * @return void
+     */
+    public function createFile($filename, $data=null) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating new files in this collection is not supported');
+
+    }
+
+    /**
+     * Creates a new directory under this object.
+     *
+     * This is currently not allowed.
+     *
+     * @param string $filename
+     * @return void
+     */
+    public function createDirectory($filename) {
+
+        throw new DAV\Exception\MethodNotAllowed('Creating new collections in this collection is not supported');
+
+    }
+
+    /**
+     * Returns a single calendar, by name
+     *
+     * @param string $name
+     * @todo needs optimizing
+     * @return \AddressBook
+     */
+    public function getChild($name) {
+
+        foreach($this->getChildren() as $child) {
+            if ($name==$child->getName())
+                return $child;
+
+        }
+        throw new DAV\Exception\NotFound('Addressbook with name \'' . $name . '\' could not be found');
+
+    }
+
+    /**
+     * Returns a list of addressbooks
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        $addressbooks = $this->carddavBackend->getAddressbooksForUser($this->principalUri);
+        $objs = array();
+        foreach($addressbooks as $addressbook) {
+            $objs[] = new AddressBook($this->carddavBackend, $addressbook);
+        }
+        return $objs;
+
+    }
+
+    /**
+     * Creates a new addressbook
+     *
+     * @param string $name
+     * @param array $resourceType
+     * @param array $properties
+     * @return void
+     */
+    public function createExtendedCollection($name, array $resourceType, array $properties) {
+
+        if (!in_array('{'.Plugin::NS_CARDDAV.'}addressbook',$resourceType) || count($resourceType)!==2) {
+            throw new DAV\Exception\InvalidResourceType('Unknown resourceType for this collection');
+        }
+        $this->carddavBackend->createAddressBook($this->principalUri, $name, $properties);
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalUri;
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->principalUri,
+                'protected' => true,
+            ),
+            array(
+                'privilege' => '{DAV:}write',
+                'principal' => $this->principalUri,
+                'protected' => true,
+            ),
+
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Changing ACL is not yet supported');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/VCFExportPlugin.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/VCFExportPlugin.php
new file mode 100644
index 0000000..bfd3790
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/VCFExportPlugin.php
@@ -0,0 +1,108 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+use OldSabre\DAV;
+use OldSabre\VObject;
+
+/**
+ * VCF Exporter
+ *
+ * This plugin adds the ability to export entire address books as .vcf files.
+ * This is useful for clients that don't support CardDAV yet. They often do
+ * support vcf files.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @author Thomas Tanghus (http://tanghus.net/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class VCFExportPlugin extends DAV\ServerPlugin {
+
+    /**
+     * Reference to Server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin and registers event handlers
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'beforeMethod'), 90);
+
+    }
+
+    /**
+     * 'beforeMethod' event handles. This event handles intercepts GET requests ending
+     * with ?export
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        if ($method!='GET') return;
+        if ($this->server->httpRequest->getQueryString()!='export') return;
+
+        // splitting uri
+        list($uri) = explode('?',$uri,2);
+
+        $node = $this->server->tree->getNodeForPath($uri);
+
+        if (!($node instanceof IAddressBook)) return;
+
+        // Checking ACL, if available.
+        if ($aclPlugin = $this->server->getPlugin('acl')) {
+            $aclPlugin->checkPrivileges($uri, '{DAV:}read');
+        }
+
+        $this->server->httpResponse->setHeader('Content-Type','text/directory');
+        $this->server->httpResponse->sendStatus(200);
+
+        $nodes = $this->server->getPropertiesForPath($uri, array(
+            '{' . Plugin::NS_CARDDAV . '}address-data',
+        ),1);
+
+        $this->server->httpResponse->sendBody($this->generateVCF($nodes));
+
+        // Returning false to break the event chain
+        return false;
+
+    }
+
+    /**
+     * Merges all vcard objects, and builds one big vcf export
+     *
+     * @param array $nodes
+     * @return string
+     */
+    public function generateVCF(array $nodes) {
+
+        $output = "";
+
+        foreach($nodes as $node) {
+
+            if (!isset($node[200]['{' . Plugin::NS_CARDDAV . '}address-data'])) {
+                continue;
+            }
+            $nodeData = $node[200]['{' . Plugin::NS_CARDDAV . '}address-data'];
+
+            // Parsing this node so VObject can clean up the output.
+            $output .=
+               VObject\Reader::read($nodeData)->serialize();
+
+        }
+
+        return $output;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Version.php b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Version.php
new file mode 100644
index 0000000..9da06a8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/CardDAV/Version.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace OldSabre\CardDAV;
+
+/**
+ * Version Class
+ *
+ * This class contains the OldSabre\CardDAV version information
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '1.8.7';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractBasic.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractBasic.php
new file mode 100644
index 0000000..986bc04
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractBasic.php
@@ -0,0 +1,87 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+
+use OldSabre\DAV;
+use OldSabre\HTTP;
+
+/**
+ * HTTP Basic authentication backend class
+ *
+ * This class can be used by authentication objects wishing to use HTTP Basic
+ * Most of the digest logic is handled, implementors just need to worry about
+ * the validateUserPass method.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author James David Low (http://jameslow.com/)
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractBasic implements BackendInterface {
+
+    /**
+     * This variable holds the currently logged in username.
+     *
+     * @var string|null
+     */
+    protected $currentUser;
+
+    /**
+     * Validates a username and password
+     *
+     * This method should return true or false depending on if login
+     * succeeded.
+     *
+     * @param string $username
+     * @param string $password
+     * @return bool
+     */
+    abstract protected function validateUserPass($username, $password);
+
+    /**
+     * Returns information about the currently logged in username.
+     *
+     * If nobody is currently logged in, this method should return null.
+     *
+     * @return string|null
+     */
+    public function getCurrentUser() {
+        return $this->currentUser;
+    }
+
+
+    /**
+     * Authenticates the user based on the current request.
+     *
+     * If authentication is successful, true must be returned.
+     * If authentication fails, an exception must be thrown.
+     *
+     * @param DAV\Server $server
+     * @param string $realm
+     * @throws DAV\Exception\NotAuthenticated
+     * @return bool
+     */
+    public function authenticate(DAV\Server $server, $realm) {
+
+        $auth = new HTTP\BasicAuth();
+        $auth->setHTTPRequest($server->httpRequest);
+        $auth->setHTTPResponse($server->httpResponse);
+        $auth->setRealm($realm);
+        $userpass = $auth->getUserPass();
+        if (!$userpass) {
+            $auth->requireLogin();
+            throw new DAV\Exception\NotAuthenticated('No basic authentication headers were found');
+        }
+
+        // Authenticates the user
+        if (!$this->validateUserPass($userpass[0],$userpass[1])) {
+            $auth->requireLogin();
+            throw new DAV\Exception\NotAuthenticated('Username or password does not match');
+        }
+        $this->currentUser = $userpass[0];
+        return true;
+    }
+
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractDigest.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractDigest.php
new file mode 100644
index 0000000..9513493
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/AbstractDigest.php
@@ -0,0 +1,101 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+
+use OldSabre\HTTP;
+use OldSabre\DAV;
+
+/**
+ * HTTP Digest authentication backend class
+ *
+ * This class can be used by authentication objects wishing to use HTTP Digest
+ * Most of the digest logic is handled, implementors just need to worry about
+ * the getDigestHash method
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractDigest implements BackendInterface {
+
+    /**
+     * This variable holds the currently logged in username.
+     *
+     * @var array|null
+     */
+    protected $currentUser;
+
+    /**
+     * Returns a users digest hash based on the username and realm.
+     *
+     * If the user was not known, null must be returned.
+     *
+     * @param string $realm
+     * @param string $username
+     * @return string|null
+     */
+    abstract public function getDigestHash($realm, $username);
+
+    /**
+     * Authenticates the user based on the current request.
+     *
+     * If authentication is successful, true must be returned.
+     * If authentication fails, an exception must be thrown.
+     *
+     * @param DAV\Server $server
+     * @param string $realm
+     * @throws DAV\Exception\NotAuthenticated
+     * @return bool
+     */
+    public function authenticate(DAV\Server $server, $realm) {
+
+        $digest = new HTTP\DigestAuth();
+
+        // Hooking up request and response objects
+        $digest->setHTTPRequest($server->httpRequest);
+        $digest->setHTTPResponse($server->httpResponse);
+
+        $digest->setRealm($realm);
+        $digest->init();
+
+        $username = $digest->getUsername();
+
+        // No username was given
+        if (!$username) {
+            $digest->requireLogin();
+            throw new DAV\Exception\NotAuthenticated('No digest authentication headers were found');
+        }
+
+        $hash = $this->getDigestHash($realm, $username);
+        // If this was false, the user account didn't exist
+        if ($hash===false || is_null($hash)) {
+            $digest->requireLogin();
+            throw new DAV\Exception\NotAuthenticated('The supplied username was not on file');
+        }
+        if (!is_string($hash)) {
+            throw new DAV\Exception('The returned value from getDigestHash must be a string or null');
+        }
+
+        // If this was false, the password or part of the hash was incorrect.
+        if (!$digest->validateA1($hash)) {
+            $digest->requireLogin();
+            throw new DAV\Exception\NotAuthenticated('Incorrect username');
+        }
+
+        $this->currentUser = $username;
+        return true;
+
+    }
+
+    /**
+     * Returns the currently logged in username.
+     *
+     * @return string|null
+     */
+    public function getCurrentUser() {
+
+        return $this->currentUser;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/Apache.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/Apache.php
new file mode 100644
index 0000000..79d94af
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/Apache.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+use OldSabre\DAV;
+
+/**
+ * Apache authenticator
+ *
+ * This authentication backend assumes that authentication has been
+ * configured in apache, rather than within SabreDAV.
+ *
+ * Make sure apache is properly configured for this to work.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Apache implements BackendInterface {
+
+    /**
+     * Current apache user
+     *
+     * @var string
+     */
+    protected $remoteUser;
+
+    /**
+     * Authenticates the user based on the current request.
+     *
+     * If authentication is successful, true must be returned.
+     * If authentication fails, an exception must be thrown.
+     *
+     * @param DAV\Server $server
+     * @param string $realm
+     * @return bool
+     */
+    public function authenticate(DAV\Server $server, $realm) {
+
+        $remoteUser = $server->httpRequest->getRawServerValue('REMOTE_USER');
+        if (is_null($remoteUser)) {
+            throw new DAV\Exception('We did not receive the $_SERVER[REMOTE_USER] property. This means that apache might have been misconfigured');
+        }
+
+        $this->remoteUser = $remoteUser;
+        return true;
+
+    }
+
+    /**
+     * Returns information about the currently logged in user.
+     *
+     * If nobody is currently logged in, this method should return null.
+     *
+     * @return array|null
+     */
+    public function getCurrentUser() {
+
+        return $this->remoteUser;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/BackendInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/BackendInterface.php
new file mode 100644
index 0000000..91241ab
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/BackendInterface.php
@@ -0,0 +1,36 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+
+/**
+ * This is the base class for any authentication object.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface BackendInterface {
+
+    /**
+     * Authenticates the user based on the current request.
+     *
+     * If authentication is successful, true must be returned.
+     * If authentication fails, an exception must be thrown.
+     *
+     * @param \OldSabre\DAV\Server $server
+     * @param string $realm
+     * @return bool
+     */
+    function authenticate(\OldSabre\DAV\Server $server,$realm);
+
+    /**
+     * Returns information about the currently logged in username.
+     *
+     * If nobody is currently logged in, this method should return null.
+     *
+     * @return string|null
+     */
+    function getCurrentUser();
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/File.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/File.php
new file mode 100644
index 0000000..8710832
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/File.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+
+use OldSabre\DAV;
+
+/**
+ * This is an authentication backend that uses a file to manage passwords.
+ *
+ * The backend file must conform to Apache's htdigest format
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class File extends AbstractDigest {
+
+    /**
+     * List of users
+     *
+     * @var array
+     */
+    protected $users = array();
+
+    /**
+     * Creates the backend object.
+     *
+     * If the filename argument is passed in, it will parse out the specified file fist.
+     *
+     * @param string|null $filename
+     */
+    public function __construct($filename=null) {
+
+        if (!is_null($filename))
+            $this->loadFile($filename);
+
+    }
+
+    /**
+     * Loads an htdigest-formatted file. This method can be called multiple times if
+     * more than 1 file is used.
+     *
+     * @param string $filename
+     * @return void
+     */
+    public function loadFile($filename) {
+
+        foreach(file($filename,FILE_IGNORE_NEW_LINES) as $line) {
+
+            if (substr_count($line, ":") !== 2)
+                throw new DAV\Exception('Malformed htdigest file. Every line should contain 2 colons');
+
+            list($username,$realm,$A1) = explode(':',$line);
+
+            if (!preg_match('/^[a-zA-Z0-9]{32}$/', $A1))
+                throw new DAV\Exception('Malformed htdigest file. Invalid md5 hash');
+
+            $this->users[$realm . ':' . $username] = $A1;
+
+        }
+
+    }
+
+    /**
+     * Returns a users' information
+     *
+     * @param string $realm
+     * @param string $username
+     * @return string
+     */
+    public function getDigestHash($realm, $username) {
+
+        return isset($this->users[$realm . ':' . $username])?$this->users[$realm . ':' . $username]:false;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/PDO.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/PDO.php
new file mode 100644
index 0000000..0b8b2be
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Backend/PDO.php
@@ -0,0 +1,65 @@
+<?php
+
+namespace OldSabre\DAV\Auth\Backend;
+
+/**
+ * This is an authentication backend that uses a file to manage passwords.
+ *
+ * The backend file must conform to Apache's htdigest format
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PDO extends AbstractDigest {
+
+    /**
+     * Reference to PDO connection
+     *
+     * @var PDO
+     */
+    protected $pdo;
+
+    /**
+     * PDO table name we'll be using
+     *
+     * @var string
+     */
+    protected $tableName;
+
+
+    /**
+     * Creates the backend object.
+     *
+     * If the filename argument is passed in, it will parse out the specified file fist.
+     *
+     * @param PDO $pdo
+     * @param string $tableName The PDO table name to use
+     */
+    public function __construct(\PDO $pdo, $tableName = 'users') {
+
+        $this->pdo = $pdo;
+        $this->tableName = $tableName;
+
+    }
+
+    /**
+     * Returns the digest hash for a user.
+     *
+     * @param string $realm
+     * @param string $username
+     * @return string|null
+     */
+    public function getDigestHash($realm,$username) {
+
+        $stmt = $this->pdo->prepare('SELECT username, digesta1 FROM '.$this->tableName.' WHERE username = ?');
+        $stmt->execute(array($username));
+        $result = $stmt->fetchAll();
+
+        if (!count($result)) return;
+
+        return $result[0]['digesta1'];
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Plugin.php
new file mode 100644
index 0000000..17106cb
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Auth/Plugin.php
@@ -0,0 +1,112 @@
+<?php
+
+namespace OldSabre\DAV\Auth;
+use OldSabre\DAV;
+
+/**
+ * This plugin provides Authentication for a WebDAV server.
+ *
+ * It relies on a Backend object, which provides user information.
+ *
+ * Additionally, it provides support for:
+ *  * {DAV:}current-user-principal property from RFC5397
+ *  * {DAV:}principal-collection-set property from RFC3744
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * Reference to main server object
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Authentication backend
+     *
+     * @var Backend\BackendInterface
+     */
+    protected $authBackend;
+
+    /**
+     * The authentication realm.
+     *
+     * @var string
+     */
+    private $realm;
+
+    /**
+     * __construct
+     *
+     * @param Backend\BackendInterface $authBackend
+     * @param string $realm
+     */
+    public function __construct(Backend\BackendInterface $authBackend, $realm) {
+
+        $this->authBackend = $authBackend;
+        $this->realm = $realm;
+
+    }
+
+    /**
+     * Initializes the plugin. This function is automatically called by the server
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'beforeMethod'),10);
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'auth';
+
+    }
+
+    /**
+     * Returns the current users' principal uri.
+     *
+     * If nobody is logged in, this will return null.
+     *
+     * @return string|null
+     */
+    public function getCurrentUser() {
+
+        $userInfo = $this->authBackend->getCurrentUser();
+        if (!$userInfo) return null;
+
+        return $userInfo;
+
+    }
+
+    /**
+     * This method is called before any HTTP method and forces users to be authenticated
+     *
+     * @param string $method
+     * @param string $uri
+     * @throws OldSabre\DAV\Exception\NotAuthenticated
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        $this->authBackend->authenticate($this->server,$this->realm);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/GuessContentType.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/GuessContentType.php
new file mode 100644
index 0000000..050a243
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/GuessContentType.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace OldSabre\DAV\Browser;
+
+use OldSabre\DAV;
+
+/**
+ * GuessContentType plugin
+ *
+ * A lot of the built-in File objects just return application/octet-stream
+ * as a content-type by default. This is a problem for some clients, because
+ * they expect a correct contenttype.
+ *
+ * There's really no accurate, fast and portable way to determine the contenttype
+ * so this extension does what the rest of the world does, and guesses it based
+ * on the file extension.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class GuessContentType extends DAV\ServerPlugin {
+
+    /**
+     * List of recognized file extensions
+     *
+     * Feel free to add more
+     *
+     * @var array
+     */
+    public $extensionMap = array(
+
+        // images
+        'jpg' => 'image/jpeg',
+        'gif' => 'image/gif',
+        'png' => 'image/png',
+
+        // groupware
+        'ics' => 'text/calendar',
+        'vcf' => 'text/x-vcard',
+
+        // text
+        'txt' => 'text/plain',
+
+    );
+
+    /**
+     * Initializes the plugin
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        // Using a relatively low priority (200) to allow other extensions
+        // to set the content-type first.
+        $server->subscribeEvent('afterGetProperties',array($this,'afterGetProperties'),200);
+
+    }
+
+    /**
+     * Handler for teh afterGetProperties event
+     *
+     * @param string $path
+     * @param array $properties
+     * @return void
+     */
+    public function afterGetProperties($path, &$properties) {
+
+        if (array_key_exists('{DAV:}getcontenttype', $properties[404])) {
+
+            list(, $fileName) = DAV\URLUtil::splitPath($path);
+            $contentType = $this->getContentType($fileName);
+
+            if ($contentType) {
+                $properties[200]['{DAV:}getcontenttype'] = $contentType;
+                unset($properties[404]['{DAV:}getcontenttype']);
+            }
+
+        }
+
+    }
+
+    /**
+     * Simple method to return the contenttype
+     *
+     * @param string $fileName
+     * @return string
+     */
+    protected function getContentType($fileName) {
+
+        // Just grabbing the extension
+        $extension = strtolower(substr($fileName,strrpos($fileName,'.')+1));
+        if (isset($this->extensionMap[$extension]))
+            return $this->extensionMap[$extension];
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/MapGetToPropFind.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/MapGetToPropFind.php
new file mode 100644
index 0000000..5d6e3c8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/MapGetToPropFind.php
@@ -0,0 +1,57 @@
+<?php
+
+namespace OldSabre\DAV\Browser;
+
+use OldSabre\DAV;
+
+/**
+ * This is a simple plugin that will map any GET request for non-files to
+ * PROPFIND allprops-requests.
+ *
+ * This should allow easy debugging of PROPFIND
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class MapGetToPropFind extends DAV\ServerPlugin {
+
+    /**
+     * reference to server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin and subscribes to events
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'httpGetInterceptor'));
+    }
+
+    /**
+     * This method intercepts GET requests to non-files, and changes it into an HTTP PROPFIND request
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function httpGetInterceptor($method, $uri) {
+
+        if ($method!='GET') return true;
+
+        $node = $this->server->tree->getNodeForPath($uri);
+        if ($node instanceof DAV\IFile) return;
+
+        $this->server->invokeMethod('PROPFIND',$uri);
+        return false;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/Plugin.php
new file mode 100644
index 0000000..7a2319b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/Plugin.php
@@ -0,0 +1,491 @@
+<?php
+
+namespace OldSabre\DAV\Browser;
+
+use OldSabre\DAV;
+
+/**
+ * Browser Plugin
+ *
+ * This plugin provides a html representation, so that a WebDAV server may be accessed
+ * using a browser.
+ *
+ * The class intercepts GET requests to collection resources and generates a simple
+ * html index.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * List of default icons for nodes.
+     *
+     * This is an array with class / interface names as keys, and asset names
+     * as values.
+     *
+     * The evaluation order is reversed. The last item in the list gets
+     * precendence.
+     *
+     * @var array
+     */
+    public $iconMap = array(
+        'OldSabre\\DAV\\IFile' => 'icons/file',
+        'OldSabre\\DAV\\ICollection' => 'icons/collection',
+        'OldSabre\\DAVACL\\IPrincipal' => 'icons/principal',
+        'OldSabre\\CalDAV\\ICalendar' => 'icons/calendar',
+        'OldSabre\\CardDAV\\IAddressBook' => 'icons/addressbook',
+        'OldSabre\\CardDAV\\ICard' => 'icons/card',
+    );
+
+    /**
+     * The file extension used for all icons
+     *
+     * @var string
+     */
+    public $iconExtension = '.png';
+
+    /**
+     * reference to server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * enablePost turns on the 'actions' panel, which allows people to create
+     * folders and upload files straight from a browser.
+     *
+     * @var bool
+     */
+    protected $enablePost = true;
+
+    /**
+     * By default the browser plugin will generate a favicon and other images.
+     * To turn this off, set this property to false.
+     *
+     * @var bool
+     */
+    protected $enableAssets = true;
+
+    /**
+     * Creates the object.
+     *
+     * By default it will allow file creation and uploads.
+     * Specify the first argument as false to disable this
+     *
+     * @param bool $enablePost
+     * @param bool $enableAssets
+     */
+    public function __construct($enablePost=true, $enableAssets = true) {
+
+        $this->enablePost = $enablePost;
+        $this->enableAssets = $enableAssets;
+
+    }
+
+    /**
+     * Initializes the plugin and subscribes to events
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'httpGetInterceptor'));
+        $this->server->subscribeEvent('onHTMLActionsPanel', array($this, 'htmlActionsPanel'),200);
+        if ($this->enablePost) $this->server->subscribeEvent('unknownMethod',array($this,'httpPOSTHandler'));
+    }
+
+    /**
+     * This method intercepts GET requests to collections and returns the html
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function httpGetInterceptor($method, $uri) {
+
+        if ($method !== 'GET') return true;
+
+        // We're not using straight-up $_GET, because we want everything to be
+        // unit testable.
+        $getVars = array();
+        parse_str($this->server->httpRequest->getQueryString(), $getVars);
+
+        if (isset($getVars['sabreAction']) && $getVars['sabreAction'] === 'asset' && isset($getVars['assetName'])) {
+            $this->serveAsset($getVars['assetName']);
+            return false;
+        }
+
+        try {
+            $node = $this->server->tree->getNodeForPath($uri);
+        } catch (DAV\Exception\NotFound $e) {
+            // We're simply stopping when the file isn't found to not interfere
+            // with other plugins.
+            return;
+        }
+        if ($node instanceof DAV\IFile)
+            return;
+
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->setHeader('Content-Type','text/html; charset=utf-8');
+
+        $this->server->httpResponse->sendBody(
+            $this->generateDirectoryIndex($uri)
+        );
+
+        return false;
+
+    }
+
+    /**
+     * Handles POST requests for tree operations.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function httpPOSTHandler($method, $uri) {
+
+        if ($method!='POST') return;
+        $contentType = $this->server->httpRequest->getHeader('Content-Type');
+        list($contentType) = explode(';', $contentType);
+        if ($contentType !== 'application/x-www-form-urlencoded' &&
+            $contentType !== 'multipart/form-data') {
+                return;
+        }
+        $postVars = $this->server->httpRequest->getPostVars();
+
+        if (!isset($postVars['sabreAction']))
+            return;
+
+        if ($this->server->broadcastEvent('onBrowserPostAction', array($uri, $postVars['sabreAction'], $postVars))) {
+
+            switch($postVars['sabreAction']) {
+
+                case 'mkcol' :
+                    if (isset($postVars['name']) && trim($postVars['name'])) {
+                        // Using basename() because we won't allow slashes
+                        list(, $folderName) = DAV\URLUtil::splitPath(trim($postVars['name']));
+                        $this->server->createDirectory($uri . '/' . $folderName);
+                    }
+                    break;
+                case 'put' :
+                    if ($_FILES) $file = current($_FILES);
+                    else break;
+
+                    list(, $newName) = DAV\URLUtil::splitPath(trim($file['name']));
+                    if (isset($postVars['name']) && trim($postVars['name']))
+                        $newName = trim($postVars['name']);
+
+                    // Making sure we only have a 'basename' component
+                    list(, $newName) = DAV\URLUtil::splitPath($newName);
+
+                    if (is_uploaded_file($file['tmp_name'])) {
+                        $this->server->createFile($uri . '/' . $newName, fopen($file['tmp_name'],'r'));
+                    }
+                    break;
+
+            }
+
+        }
+        $this->server->httpResponse->setHeader('Location',$this->server->httpRequest->getUri());
+        $this->server->httpResponse->sendStatus(302);
+        return false;
+
+    }
+
+    /**
+     * Escapes a string for html.
+     *
+     * @param string $value
+     * @return string
+     */
+    public function escapeHTML($value) {
+
+        return htmlspecialchars($value,ENT_QUOTES,'UTF-8');
+
+    }
+
+    /**
+     * Generates the html directory index for a given url
+     *
+     * @param string $path
+     * @return string
+     */
+    public function generateDirectoryIndex($path) {
+
+        $version = '';
+        if (DAV\Server::$exposeVersion) {
+            $version = DAV\Version::VERSION ."-". DAV\Version::STABILITY;
+        }
+
+        $html = "<html>
+<head>
+  <title>Index for " . $this->escapeHTML($path) . "/ - SabreDAV " . $version . "</title>
+  <style type=\"text/css\">
+  body { Font-family: arial}
+  h1 { font-size: 150% }
+  </style>
+        ";
+
+        if ($this->enableAssets) {
+            $html.='<link rel="shortcut icon" href="'.$this->getAssetUrl('favicon.ico').'" type="image/vnd.microsoft.icon" />';
+        }
+
+        $html .= "</head>
+<body>
+  <h1>Index for " . $this->escapeHTML($path) . "/</h1>
+  <table>
+    <tr><th width=\"24\"></th><th>Name</th><th>Type</th><th>Size</th><th>Last modified</th></tr>
+    <tr><td colspan=\"5\"><hr /></td></tr>";
+
+        $files = $this->server->getPropertiesForPath($path,array(
+            '{DAV:}displayname',
+            '{DAV:}resourcetype',
+            '{DAV:}getcontenttype',
+            '{DAV:}getcontentlength',
+            '{DAV:}getlastmodified',
+        ),1);
+
+        $parent = $this->server->tree->getNodeForPath($path);
+
+
+        if ($path) {
+
+            list($parentUri) = DAV\URLUtil::splitPath($path);
+            $fullPath = DAV\URLUtil::encodePath($this->server->getBaseUri() . $parentUri);
+
+            $icon = $this->enableAssets?'<a href="' . $fullPath . '"><img src="' . $this->getAssetUrl('icons/parent' . $this->iconExtension) . '" width="24" alt="Parent" /></a>':'';
+            $html.= "<tr>
+    <td>$icon</td>
+    <td><a href=\"{$fullPath}\">..</a></td>
+    <td>[parent]</td>
+    <td></td>
+    <td></td>
+    </tr>";
+
+        }
+
+        foreach($files as $file) {
+
+            // This is the current directory, we can skip it
+            if (rtrim($file['href'],'/')==$path) continue;
+
+            list(, $name) = DAV\URLUtil::splitPath($file['href']);
+
+            $type = null;
+
+
+            if (isset($file[200]['{DAV:}resourcetype'])) {
+                $type = $file[200]['{DAV:}resourcetype']->getValue();
+
+                // resourcetype can have multiple values
+                if (!is_array($type)) $type = array($type);
+
+                foreach($type as $k=>$v) {
+
+                    // Some name mapping is preferred
+                    switch($v) {
+                        case '{DAV:}collection' :
+                            $type[$k] = 'Collection';
+                            break;
+                        case '{DAV:}principal' :
+                            $type[$k] = 'Principal';
+                            break;
+                        case '{urn:ietf:params:xml:ns:carddav}addressbook' :
+                            $type[$k] = 'Addressbook';
+                            break;
+                        case '{urn:ietf:params:xml:ns:caldav}calendar' :
+                            $type[$k] = 'Calendar';
+                            break;
+                        case '{urn:ietf:params:xml:ns:caldav}schedule-inbox' :
+                            $type[$k] = 'Schedule Inbox';
+                            break;
+                        case '{urn:ietf:params:xml:ns:caldav}schedule-outbox' :
+                            $type[$k] = 'Schedule Outbox';
+                            break;
+                        case '{http://calendarserver.org/ns/}calendar-proxy-read' :
+                            $type[$k] = 'Proxy-Read';
+                            break;
+                        case '{http://calendarserver.org/ns/}calendar-proxy-write' :
+                            $type[$k] = 'Proxy-Write';
+                            break;
+                    }
+
+                }
+                $type = implode(', ', $type);
+            }
+
+            // If no resourcetype was found, we attempt to use
+            // the contenttype property
+            if (!$type && isset($file[200]['{DAV:}getcontenttype'])) {
+                $type = $file[200]['{DAV:}getcontenttype'];
+            }
+            if (!$type) $type = 'Unknown';
+
+            $size = isset($file[200]['{DAV:}getcontentlength'])?(int)$file[200]['{DAV:}getcontentlength']:'';
+            $lastmodified = isset($file[200]['{DAV:}getlastmodified'])?$file[200]['{DAV:}getlastmodified']->getTime()->format(\DateTime::ATOM):'';
+
+            $fullPath = DAV\URLUtil::encodePath('/' . trim($this->server->getBaseUri() . ($path?$path . '/':'') . $name,'/'));
+
+            $displayName = isset($file[200]['{DAV:}displayname'])?$file[200]['{DAV:}displayname']:$name;
+
+            $displayName = $this->escapeHTML($displayName);
+            $type = $this->escapeHTML($type);
+
+            $icon = '';
+
+            if ($this->enableAssets) {
+                $node = $this->server->tree->getNodeForPath(($path?$path.'/':'') . $name);
+                foreach(array_reverse($this->iconMap) as $class=>$iconName) {
+
+                    if ($node instanceof $class) {
+                        $icon = '<a href="' . $fullPath . '"><img src="' . $this->getAssetUrl($iconName . $this->iconExtension) . '" alt="" width="24" /></a>';
+                        break;
+                    }
+
+
+                }
+
+            }
+
+            $html.= "<tr>
+    <td>$icon</td>
+    <td><a href=\"{$fullPath}\">{$displayName}</a></td>
+    <td>{$type}</td>
+    <td>{$size}</td>
+    <td>{$lastmodified}</td>
+    </tr>";
+
+        }
+
+        $html.= "<tr><td colspan=\"5\"><hr /></td></tr>";
+
+        $output = '';
+
+        if ($this->enablePost) {
+            $this->server->broadcastEvent('onHTMLActionsPanel',array($parent, &$output));
+        }
+
+        $html.=$output;
+
+        $html.= "</table>
+        <address>Generated by SabreDAV " . $version . " (c)2007-2015 <a href=\"http://sabre.io/\">http://sabre.io/</a></address>
+        </body>
+        </html>";
+
+        return $html;
+
+    }
+
+    /**
+     * This method is used to generate the 'actions panel' output for
+     * collections.
+     *
+     * This specifically generates the interfaces for creating new files, and
+     * creating new directories.
+     *
+     * @param DAV\INode $node
+     * @param mixed $output
+     * @return void
+     */
+    public function htmlActionsPanel(DAV\INode $node, &$output) {
+
+        if (!$node instanceof DAV\ICollection)
+            return;
+
+        // We also know fairly certain that if an object is a non-extended
+        // SimpleCollection, we won't need to show the panel either.
+        if (get_class($node)==='OldSabre\\DAV\\SimpleCollection')
+            return;
+
+        $output.= '<tr><td colspan="2"><form method="post" action="">
+            <h3>Create new folder</h3>
+            <input type="hidden" name="sabreAction" value="mkcol" />
+            Name: <input type="text" name="name" /><br />
+            <input type="submit" value="create" />
+            </form>
+            <form method="post" action="" enctype="multipart/form-data">
+            <h3>Upload file</h3>
+            <input type="hidden" name="sabreAction" value="put" />
+            Name (optional): <input type="text" name="name" /><br />
+            File: <input type="file" name="file" /><br />
+            <input type="submit" value="upload" />
+            </form>
+            </td></tr>';
+
+    }
+
+    /**
+     * This method takes a path/name of an asset and turns it into url
+     * suiteable for http access.
+     *
+     * @param string $assetName
+     * @return string
+     */
+    protected function getAssetUrl($assetName) {
+
+        return $this->server->getBaseUri() . '?sabreAction=asset&assetName=' . urlencode($assetName);
+
+    }
+
+    /**
+     * This method returns a local pathname to an asset.
+     *
+     * @param string $assetName
+     * @return string
+     */
+    protected function getLocalAssetPath($assetName) {
+
+        $assetDir = __DIR__ . '/assets/';
+        $path = $assetDir . $assetName;
+
+        // Making sure people aren't trying to escape from the base path.
+        if (strpos(realpath($path), realpath($assetDir)) === 0) {
+            return $path;
+        }
+        throw new DAV\Exception\Forbidden('Path does not exist, or escaping from the base path was detected');
+    }
+
+    /**
+     * This method reads an asset from disk and generates a full http response.
+     *
+     * @param string $assetName
+     * @return void
+     */
+    protected function serveAsset($assetName) {
+
+        $assetPath = $this->getLocalAssetPath($assetName);
+        if (!file_exists($assetPath)) {
+            throw new DAV\Exception\NotFound('Could not find an asset with this name');
+        }
+        // Rudimentary mime type detection
+        switch(strtolower(substr($assetPath,strpos($assetPath,'.')+1))) {
+
+        case 'ico' :
+            $mime = 'image/vnd.microsoft.icon';
+            break;
+
+        case 'png' :
+            $mime = 'image/png';
+            break;
+
+        default:
+            $mime = 'application/octet-stream';
+            break;
+
+        }
+
+        $this->server->httpResponse->setHeader('Content-Type', $mime);
+        $this->server->httpResponse->setHeader('Content-Length', filesize($assetPath));
+        $this->server->httpResponse->setHeader('Cache-Control', 'public, max-age=1209600');
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->sendBody(fopen($assetPath,'r'));
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/favicon.ico b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/favicon.ico
new file mode 100644
index 0000000..2b2c10a
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/favicon.ico
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/addressbook.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/addressbook.png
new file mode 100644
index 0000000..c9acc84
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/addressbook.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/calendar.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/calendar.png
new file mode 100644
index 0000000..3ecd6a8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/calendar.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/card.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/card.png
new file mode 100644
index 0000000..2ce9548
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/card.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/collection.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/collection.png
new file mode 100644
index 0000000..156fa64
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/collection.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/file.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/file.png
new file mode 100644
index 0000000..3b98551
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/file.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/parent.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/parent.png
new file mode 100644
index 0000000..156fa64
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/parent.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/principal.png b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/principal.png
new file mode 100644
index 0000000..f8988f8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Browser/assets/icons/principal.png
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Client.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Client.php
new file mode 100644
index 0000000..22a44ba
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Client.php
@@ -0,0 +1,578 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * SabreDAV DAV client
+ *
+ * This client wraps around Curl to provide a convenient API to a WebDAV
+ * server.
+ *
+ * NOTE: This class is experimental, it's api will likely change in the future.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Client {
+
+    /**
+     * The propertyMap is a key-value array.
+     *
+     * If you use the propertyMap, any {DAV:}multistatus responses with the
+     * proeprties listed in this array, will automatically be mapped to a
+     * respective class.
+     *
+     * The {DAV:}resourcetype property is automatically added. This maps to
+     * OldSabre\DAV\Property\ResourceType
+     *
+     * @var array
+     */
+    public $propertyMap = array();
+
+    protected $baseUri;
+    protected $userName;
+    protected $password;
+    protected $proxy;
+    protected $trustedCertificates;
+
+    /**
+     * Basic authentication
+     */
+    const AUTH_BASIC = 1;
+
+    /**
+     * Digest authentication
+     */
+    const AUTH_DIGEST = 2;
+
+    /**
+     * The authentication type we're using.
+     *
+     * This is a bitmask of AUTH_BASIC and AUTH_DIGEST.
+     *
+     * If DIGEST is used, the client makes 1 extra request per request, to get
+     * the authentication tokens.
+     *
+     * @var int
+     */
+    protected $authType;
+
+    /**
+     * Indicates if SSL verification is enabled or not.
+     *
+     * @var boolean
+     */
+    protected $verifyPeer;
+
+    /**
+     * Constructor
+     *
+     * Settings are provided through the 'settings' argument. The following
+     * settings are supported:
+     *
+     *   * baseUri
+     *   * userName (optional)
+     *   * password (optional)
+     *   * proxy (optional)
+     *
+     * @param array $settings
+     */
+    public function __construct(array $settings) {
+
+        if (!isset($settings['baseUri'])) {
+            throw new \InvalidArgumentException('A baseUri must be provided');
+        }
+
+        $validSettings = array(
+            'baseUri',
+            'userName',
+            'password',
+            'proxy',
+        );
+
+        foreach($validSettings as $validSetting) {
+            if (isset($settings[$validSetting])) {
+                $this->$validSetting = $settings[$validSetting];
+            }
+        }
+
+        if (isset($settings['authType'])) {
+            $this->authType = $settings['authType'];
+        } else {
+            $this->authType = self::AUTH_BASIC | self::AUTH_DIGEST;
+        }
+
+        $this->propertyMap['{DAV:}resourcetype'] = 'OldSabre\\DAV\\Property\\ResourceType';
+
+    }
+
+    /**
+     * Add trusted root certificates to the webdav client.
+     *
+     * The parameter certificates should be a absolute path to a file
+     * which contains all trusted certificates
+     *
+     * @param string $certificates
+     */
+    public function addTrustedCertificates($certificates) {
+        $this->trustedCertificates = $certificates;
+    }
+
+    /**
+     * Enables/disables SSL peer verification
+     *
+     * @param boolean $value
+     */
+    public function setVerifyPeer($value) {
+        $this->verifyPeer = $value;
+    }
+
+    /**
+     * Does a PROPFIND request
+     *
+     * The list of requested properties must be specified as an array, in clark
+     * notation.
+     *
+     * The returned array will contain a list of filenames as keys, and
+     * properties as values.
+     *
+     * The properties array will contain the list of properties. Only properties
+     * that are actually returned from the server (without error) will be
+     * returned, anything else is discarded.
+     *
+     * Depth should be either 0 or 1. A depth of 1 will cause a request to be
+     * made to the server to also return all child resources.
+     *
+     * @param string $url
+     * @param array $properties
+     * @param int $depth
+     * @return array
+     */
+    public function propFind($url, array $properties, $depth = 0) {
+
+        $body = '<?xml version="1.0"?>' . "\n";
+        $body.= '<d:propfind xmlns:d="DAV:">' . "\n";
+        $body.= '  <d:prop>' . "\n";
+
+        foreach($properties as $property) {
+
+            list(
+                $namespace,
+                $elementName
+            ) = XMLUtil::parseClarkNotation($property);
+
+            if ($namespace === 'DAV:') {
+                $body.='    <d:' . $elementName . ' />' . "\n";
+            } else {
+                $body.="    <x:" . $elementName . " xmlns:x=\"" . $namespace . "\"/>\n";
+            }
+
+        }
+
+        $body.= '  </d:prop>' . "\n";
+        $body.= '</d:propfind>';
+
+        $response = $this->request('PROPFIND', $url, $body, array(
+            'Depth' => $depth,
+            'Content-Type' => 'application/xml'
+        ));
+
+        $result = $this->parseMultiStatus($response['body']);
+
+        // If depth was 0, we only return the top item
+        if ($depth===0) {
+            reset($result);
+            $result = current($result);
+            return isset($result[200])?$result[200]:array();
+        }
+
+        $newResult = array();
+        foreach($result as $href => $statusList) {
+
+            $newResult[$href] = isset($statusList[200])?$statusList[200]:array();
+
+        }
+
+        return $newResult;
+
+    }
+
+    /**
+     * Updates a list of properties on the server
+     *
+     * The list of properties must have clark-notation properties for the keys,
+     * and the actual (string) value for the value. If the value is null, an
+     * attempt is made to delete the property.
+     *
+     * @todo Must be building the request using the DOM, and does not yet
+     *       support complex properties.
+     * @param string $url
+     * @param array $properties
+     * @return void
+     */
+    public function propPatch($url, array $properties) {
+
+        $body = '<?xml version="1.0"?>' . "\n";
+        $body.= '<d:propertyupdate xmlns:d="DAV:">' . "\n";
+
+        foreach($properties as $propName => $propValue) {
+
+            list(
+                $namespace,
+                $elementName
+            ) = XMLUtil::parseClarkNotation($propName);
+
+            if ($propValue === null) {
+
+                $body.="<d:remove><d:prop>\n";
+
+                if ($namespace === 'DAV:') {
+                    $body.='    <d:' . $elementName . ' />' . "\n";
+                } else {
+                    $body.="    <x:" . $elementName . " xmlns:x=\"" . $namespace . "\"/>\n";
+                }
+
+                $body.="</d:prop></d:remove>\n";
+
+            } else {
+
+                $body.="<d:set><d:prop>\n";
+                if ($namespace === 'DAV:') {
+                    $body.='    <d:' . $elementName . '>';
+                } else {
+                    $body.="    <x:" . $elementName . " xmlns:x=\"" . $namespace . "\">";
+                }
+                // Shitty.. i know
+                $body.=htmlspecialchars($propValue, ENT_NOQUOTES, 'UTF-8');
+                if ($namespace === 'DAV:') {
+                    $body.='</d:' . $elementName . '>' . "\n";
+                } else {
+                    $body.="</x:" . $elementName . ">\n";
+                }
+                $body.="</d:prop></d:set>\n";
+
+            }
+
+        }
+
+        $body.= '</d:propertyupdate>';
+
+        $this->request('PROPPATCH', $url, $body, array(
+            'Content-Type' => 'application/xml'
+        ));
+
+    }
+
+    /**
+     * Performs an HTTP options request
+     *
+     * This method returns all the features from the 'DAV:' header as an array.
+     * If there was no DAV header, or no contents this method will return an
+     * empty array.
+     *
+     * @return array
+     */
+    public function options() {
+
+        $result = $this->request('OPTIONS');
+        if (!isset($result['headers']['dav'])) {
+            return array();
+        }
+
+        $features = explode(',', $result['headers']['dav']);
+        foreach($features as &$v) {
+            $v = trim($v);
+        }
+        return $features;
+
+    }
+
+    /**
+     * Performs an actual HTTP request, and returns the result.
+     *
+     * If the specified url is relative, it will be expanded based on the base
+     * url.
+     *
+     * The returned array contains 3 keys:
+     *   * body - the response body
+     *   * httpCode - a HTTP code (200, 404, etc)
+     *   * headers - a list of response http headers. The header names have
+     *     been lowercased.
+     *
+     * @param string $method
+     * @param string $url
+     * @param string $body
+     * @param array $headers
+     * @return array
+     */
+    public function request($method, $url = '', $body = null, $headers = array()) {
+
+        $url = $this->getAbsoluteUrl($url);
+
+        $curlSettings = array(
+            CURLOPT_RETURNTRANSFER => true,
+            // Return headers as part of the response
+            CURLOPT_HEADER => true,
+
+            // For security we cast this to a string. If somehow an array could
+            // be passed here, it would be possible for an attacker to use @ to
+            // post local files.
+            CURLOPT_POSTFIELDS => (string)$body,
+            // Automatically follow redirects
+            CURLOPT_FOLLOWLOCATION => true,
+            CURLOPT_MAXREDIRS => 5,
+            CURLOPT_PROTOCOLS => CURLPROTO_HTTP | CURLPROTO_HTTPS,
+            CURLOPT_REDIR_PROTOCOLS => CURLPROTO_HTTP | CURLPROTO_HTTPS
+        );
+
+        if($this->verifyPeer !== null) {
+            $curlSettings[CURLOPT_SSL_VERIFYPEER] = $this->verifyPeer;
+            $curlSettings[CURLOPT_SSL_VERIFYHOST] = $this->verifyPeer;
+        }
+
+        if($this->trustedCertificates) {
+            $curlSettings[CURLOPT_CAINFO] = $this->trustedCertificates;
+        }
+
+        switch ($method) {
+            case 'HEAD' :
+
+                // do not read body with HEAD requests (this is necessary because cURL does not ignore the body with HEAD
+                // requests when the Content-Length header is given - which in turn is perfectly valid according to HTTP
+                // specs...) cURL does unfortunately return an error in this case ("transfer closed transfer closed with
+                // ... bytes remaining to read") this can be circumvented by explicitly telling cURL to ignore the
+                // response body
+                $curlSettings[CURLOPT_NOBODY] = true;
+                $curlSettings[CURLOPT_CUSTOMREQUEST] = 'HEAD';
+                break;
+
+            default:
+                $curlSettings[CURLOPT_CUSTOMREQUEST] = $method;
+                break;
+
+        }
+
+        // Adding HTTP headers
+        $nHeaders = array();
+        foreach($headers as $key=>$value) {
+
+            $nHeaders[] = $key . ': ' . $value;
+
+        }
+        $curlSettings[CURLOPT_HTTPHEADER] = $nHeaders;
+
+        if ($this->proxy) {
+            $curlSettings[CURLOPT_PROXY] = $this->proxy;
+        }
+
+        if ($this->userName && $this->authType) {
+            $curlType = 0;
+            if ($this->authType & self::AUTH_BASIC) {
+                $curlType |= CURLAUTH_BASIC;
+            }
+            if ($this->authType & self::AUTH_DIGEST) {
+                $curlType |= CURLAUTH_DIGEST;
+            }
+            $curlSettings[CURLOPT_HTTPAUTH] = $curlType;
+            $curlSettings[CURLOPT_USERPWD] = $this->userName . ':' . $this->password;
+        }
+
+        list(
+            $response,
+            $curlInfo,
+            $curlErrNo,
+            $curlError
+        ) = $this->curlRequest($url, $curlSettings);
+
+        $headerBlob = substr($response, 0, $curlInfo['header_size']);
+        $response = substr($response, $curlInfo['header_size']);
+
+        // In the case of 100 Continue, or redirects we'll have multiple lists
+        // of headers for each separate HTTP response. We can easily split this
+        // because they are separated by \r\n\r\n
+        $headerBlob = explode("\r\n\r\n", trim($headerBlob, "\r\n"));
+
+        // We only care about the last set of headers
+        $headerBlob = $headerBlob[count($headerBlob)-1];
+
+        // Splitting headers
+        $headerBlob = explode("\r\n", $headerBlob);
+
+        $headers = array();
+        foreach($headerBlob as $header) {
+            $parts = explode(':', $header, 2);
+            if (count($parts)==2) {
+                $headers[strtolower(trim($parts[0]))] = trim($parts[1]);
+            }
+        }
+
+        $response = array(
+            'body' => $response,
+            'statusCode' => $curlInfo['http_code'],
+            'headers' => $headers
+        );
+
+        if ($curlErrNo) {
+            throw new Exception('[CURL] Error while making request: ' . $curlError . ' (error code: ' . $curlErrNo . ')');
+        }
+
+        if ($response['statusCode']>=400) {
+            switch ($response['statusCode']) {
+                case 400 :
+                    throw new Exception\BadRequest('Bad request');
+                case 401 :
+                    throw new Exception\NotAuthenticated('Not authenticated');
+                case 402 :
+                    throw new Exception\PaymentRequired('Payment required');
+                case 403 :
+                    throw new Exception\Forbidden('Forbidden');
+                case 404:
+                    throw new Exception\NotFound('Resource not found.');
+                case 405 :
+                    throw new Exception\MethodNotAllowed('Method not allowed');
+                case 409 :
+                    throw new Exception\Conflict('Conflict');
+                case 412 :
+                    throw new Exception\PreconditionFailed('Precondition failed');
+                case 416 :
+                    throw new Exception\RequestedRangeNotSatisfiable('Requested Range Not Satisfiable');
+                case 500 :
+                    throw new Exception('Internal server error');
+                case 501 :
+                    throw new Exception\NotImplemented('Not Implemented');
+                case 507 :
+                    throw new Exception\InsufficientStorage('Insufficient storage');
+                default:
+                    throw new Exception('HTTP error response. (errorcode ' . $response['statusCode'] . ')');
+            }
+        }
+
+        return $response;
+
+    }
+
+    /**
+     * Wrapper for all curl functions.
+     *
+     * The only reason this was split out in a separate method, is so it
+     * becomes easier to unittest.
+     *
+     * @param string $url
+     * @param array $settings
+     * @return array
+     */
+    // @codeCoverageIgnoreStart
+    protected function curlRequest($url, $settings) {
+
+        $curl = curl_init($url);
+        curl_setopt_array($curl, $settings);
+
+        return array(
+            curl_exec($curl),
+            curl_getinfo($curl),
+            curl_errno($curl),
+            curl_error($curl)
+        );
+
+    }
+    // @codeCoverageIgnoreEnd
+
+    /**
+     * Returns the full url based on the given url (which may be relative). All
+     * urls are expanded based on the base url as given by the server.
+     *
+     * @param string $url
+     * @return string
+     */
+    protected function getAbsoluteUrl($url) {
+
+        // If the url starts with http:// or https://, the url is already absolute.
+        if (preg_match('/^http(s?):\/\//', $url)) {
+            return $url;
+        }
+
+        // If the url starts with a slash, we must calculate the url based off
+        // the root of the base url.
+        if (strpos($url,'/') === 0) {
+            $parts = parse_url($this->baseUri);
+            return $parts['scheme'] . '://' . $parts['host'] . (isset($parts['port'])?':' . $parts['port']:'') . $url;
+        }
+
+        // Otherwise...
+        return $this->baseUri . $url;
+
+    }
+
+    /**
+     * Parses a WebDAV multistatus response body
+     *
+     * This method returns an array with the following structure
+     *
+     * array(
+     *   'url/to/resource' => array(
+     *     '200' => array(
+     *        '{DAV:}property1' => 'value1',
+     *        '{DAV:}property2' => 'value2',
+     *     ),
+     *     '404' => array(
+     *        '{DAV:}property1' => null,
+     *        '{DAV:}property2' => null,
+     *     ),
+     *   )
+     *   'url/to/resource2' => array(
+     *      .. etc ..
+     *   )
+     * )
+     *
+     *
+     * @param string $body xml body
+     * @return array
+     */
+    public function parseMultiStatus($body) {
+
+        $body = XMLUtil::convertDAVNamespace($body);
+
+        // Fixes an XXE vulnerability on PHP versions older than 5.3.23 or
+        // 5.4.13.
+        $previous = libxml_disable_entity_loader(true);
+        $responseXML = simplexml_load_string($body, null, LIBXML_NOBLANKS | LIBXML_NOCDATA);
+        libxml_disable_entity_loader($previous);
+
+        if ($responseXML===false) {
+            throw new \InvalidArgumentException('The passed data is not valid XML');
+        }
+
+        $responseXML->registerXPathNamespace('d', 'urn:DAV');
+
+        $propResult = array();
+
+        foreach($responseXML->xpath('d:response') as $response) {
+            $response->registerXPathNamespace('d', 'urn:DAV');
+            $href = $response->xpath('d:href');
+            $href = (string)$href[0];
+
+            $properties = array();
+
+            foreach($response->xpath('d:propstat') as $propStat) {
+
+                $propStat->registerXPathNamespace('d', 'urn:DAV');
+                $status = $propStat->xpath('d:status');
+                list($httpVersion, $statusCode, $message) = explode(' ', (string)$status[0],3);
+
+                // Only using the propertymap for results with status 200.
+                $propertyMap = $statusCode==='200' ? $this->propertyMap : array();
+
+                $properties[$statusCode] = XMLUtil::parseProperties(dom_import_simplexml($propStat), $propertyMap);
+
+            }
+
+            $propResult[$href] = $properties;
+
+        }
+
+        return $propResult;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Collection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Collection.php
new file mode 100644
index 0000000..855667e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Collection.php
@@ -0,0 +1,110 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * Collection class
+ *
+ * This is a helper class, that should aid in getting collections classes setup.
+ * Most of its methods are implemented, and throw permission denied exceptions
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Collection extends Node implements ICollection {
+
+    /**
+     * Returns a child object, by its name.
+     *
+     * This method makes use of the getChildren method to grab all the child
+     * nodes, and compares the name.
+     * Generally its wise to override this, as this can usually be optimized
+     *
+     * This method must throw OldSabre\DAV\Exception\NotFound if the node does not
+     * exist.
+     *
+     * @param string $name
+     * @throws Exception\NotFound
+     * @return INode
+     */
+    public function getChild($name) {
+
+        foreach($this->getChildren() as $child) {
+
+            if ($child->getName()==$name) return $child;
+
+        }
+        throw new Exception\NotFound('File not found: ' . $name);
+
+    }
+
+    /**
+     * Checks is a child-node exists.
+     *
+     * It is generally a good idea to try and override this. Usually it can be optimized.
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function childExists($name) {
+
+        try {
+
+            $this->getChild($name);
+            return true;
+
+        } catch(Exception\NotFound $e) {
+
+            return false;
+
+        }
+
+    }
+
+    /**
+     * Creates a new file in the directory
+     *
+     * Data will either be supplied as a stream resource, or in certain cases
+     * as a string. Keep in mind that you may have to support either.
+     *
+     * After succesful creation of the file, you may choose to return the ETag
+     * of the new file here.
+     *
+     * The returned ETag must be surrounded by double-quotes (The quotes should
+     * be part of the actual string).
+     *
+     * If you cannot accurately determine the ETag, you should not return it.
+     * If you don't store the file exactly as-is (you're transforming it
+     * somehow) you should also not return an ETag.
+     *
+     * This means that if a subsequent GET to this new file does not exactly
+     * return the same contents of what was submitted here, you are strongly
+     * recommended to omit the ETag.
+     *
+     * @param string $name Name of the file
+     * @param resource|string $data Initial payload
+     * @return null|string
+     */
+    public function createFile($name, $data = null) {
+
+        throw new Exception\Forbidden('Permission denied to create file (filename ' . $name . ')');
+
+    }
+
+    /**
+     * Creates a new subdirectory
+     *
+     * @param string $name
+     * @throws Exception\Forbidden
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        throw new Exception\Forbidden('Permission denied to create directory');
+
+    }
+
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception.php
new file mode 100644
index 0000000..357e818
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception.php
@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * SabreDAV base exception
+ *
+ * This is SabreDAV's base exception file, use this to implement your own exception.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+
+namespace OldSabre\DAV;
+
+/**
+ * Main Exception class.
+ *
+ * This class defines a getHTTPCode method, which should return the appropriate HTTP code for the Exception occurred.
+ * The default for this is 500.
+ *
+ * This class also allows you to generate custom xml data for your exceptions. This will be displayed
+ * in the 'error' element in the failing response.
+ */
+class Exception extends \Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 500;
+
+    }
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(Server $server,\DOMElement $errorNode) {
+
+
+    }
+
+    /**
+     * This method allows the exception to return any extra HTTP response headers.
+     *
+     * The headers must be returned as an array.
+     *
+     * @param Server $server
+     * @return array
+     */
+    public function getHTTPHeaders(Server $server) {
+
+        return array();
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/BadRequest.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/BadRequest.php
new file mode 100644
index 0000000..aeb6350
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/BadRequest.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * BadRequest
+ *
+ * The BadRequest is thrown when the user submitted an invalid HTTP request
+ * BadRequest
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class BadRequest extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 400;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Conflict.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Conflict.php
new file mode 100644
index 0000000..97ef2cd
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Conflict.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * Conflict
+ *
+ * A 409 Conflict is thrown when a user tried to make a directory over an existing
+ * file or in a parent directory that doesn't exist.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Conflict extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 409;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ConflictingLock.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ConflictingLock.php
new file mode 100644
index 0000000..33839d3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ConflictingLock.php
@@ -0,0 +1,37 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * ConflictingLock
+ *
+ * Similar to  the Locked exception, this exception thrown when a LOCK request
+ * was made, on a resource which was already locked
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ConflictingLock extends Locked {
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $errorNode) {
+
+        if ($this->lock) {
+            $error = $errorNode->ownerDocument->createElementNS('DAV:','d:no-conflicting-lock');
+            $errorNode->appendChild($error);
+            if (!is_object($this->lock)) var_dump($this->lock);
+            $error->appendChild($errorNode->ownerDocument->createElementNS('DAV:','d:href',$this->lock->uri));
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/FileNotFound.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/FileNotFound.php
new file mode 100644
index 0000000..f35f9b3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/FileNotFound.php
@@ -0,0 +1,19 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * FileNotFound
+ *
+ * Deprecated: Warning, this class is deprecated and will be removed in a
+ * future version of SabreDAV. Please use OldSabre\DAV\Exception\NotFound instead.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @deprecated Use OldSabre\DAV\Exception\NotFound instead
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class FileNotFound extends NotFound {
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Forbidden.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Forbidden.php
new file mode 100644
index 0000000..003d86b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Forbidden.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * Forbidden
+ *
+ * This exception is thrown whenever a user tries to do an operation he's not allowed to
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Forbidden extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 403;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InsufficientStorage.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InsufficientStorage.php
new file mode 100644
index 0000000..081a3e4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InsufficientStorage.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * InsufficientStorage
+ *
+ * This Exception can be thrown, when for example a harddisk is full or a quota is exceeded
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class InsufficientStorage extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 507;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InvalidResourceType.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InvalidResourceType.php
new file mode 100644
index 0000000..9526b8d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/InvalidResourceType.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * InvalidResourceType
+ *
+ * This exception is thrown when the user tried to create a new collection, with
+ * a special resourcetype value that was not recognized by the server.
+ *
+ * See RFC5689 section 3.3
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class InvalidResourceType extends Forbidden {
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(\OldSabre\DAV\Server $server,\DOMElement $errorNode) {
+
+        $error = $errorNode->ownerDocument->createElementNS('DAV:','d:valid-resourcetype');
+        $errorNode->appendChild($error);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LengthRequired.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LengthRequired.php
new file mode 100644
index 0000000..39cd639
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LengthRequired.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * LengthRequired
+ *
+ * This exception is thrown when a request was made that required a
+ * Content-Length header, but did not contain one.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class LengthRequired extends DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 411;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LockTokenMatchesRequestUri.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LockTokenMatchesRequestUri.php
new file mode 100644
index 0000000..08d94b5
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/LockTokenMatchesRequestUri.php
@@ -0,0 +1,41 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * LockTokenMatchesRequestUri
+ *
+ * This exception is thrown by UNLOCK if a supplied lock-token is invalid
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class LockTokenMatchesRequestUri extends Conflict {
+
+    /**
+     * Creates the exception
+     */
+    public function __construct() {
+
+        $this->message = 'The locktoken supplied does not match any locks on this entity';
+
+    }
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $error = $errorNode->ownerDocument->createElementNS('DAV:','d:lock-token-matches-request-uri');
+        $errorNode->appendChild($error);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Locked.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Locked.php
new file mode 100644
index 0000000..4d38357
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/Locked.php
@@ -0,0 +1,73 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * Locked
+ *
+ * The 423 is thrown when a client tried to access a resource that was locked, without supplying a valid lock token
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Locked extends DAV\Exception {
+
+    /**
+     * Lock information
+     *
+     * @var OldSabre\DAV\Locks\LockInfo
+     */
+    protected $lock;
+
+    /**
+     * Creates the exception
+     *
+     * A LockInfo object should be passed if the user should be informed
+     * which lock actually has the file locked.
+     *
+     * @param DAV\Locks\LockInfo $lock
+     */
+    public function __construct(DAV\Locks\LockInfo $lock = null) {
+
+        $this->lock = $lock;
+
+    }
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 423;
+
+    }
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        if ($this->lock) {
+            $error = $errorNode->ownerDocument->createElementNS('DAV:','d:lock-token-submitted');
+            $errorNode->appendChild($error);
+
+            $href = $errorNode->ownerDocument->createElementNS('DAV:','d:href');
+            $href->appendChild($errorNode->ownerDocument->createTextNode($this->lock->uri));
+            $error->appendChild(
+                $href
+            );
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/MethodNotAllowed.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/MethodNotAllowed.php
new file mode 100644
index 0000000..adf91e2
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/MethodNotAllowed.php
@@ -0,0 +1,45 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * MethodNotAllowed
+ *
+ * The 405 is thrown when a client tried to create a directory on an already existing directory
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class MethodNotAllowed extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 405;
+
+    }
+
+    /**
+     * This method allows the exception to return any extra HTTP response headers.
+     *
+     * The headers must be returned as an array.
+     *
+     * @param \OldSabre\DAV\Server $server
+     * @return array
+     */
+    public function getHTTPHeaders(\OldSabre\DAV\Server $server) {
+
+        $methods = $server->getAllowedMethods($server->getRequestUri());
+
+        return array(
+            'Allow' => strtoupper(implode(', ',$methods)),
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotAuthenticated.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotAuthenticated.php
new file mode 100644
index 0000000..2e98802
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotAuthenticated.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * NotAuthenticated
+ *
+ * This exception is thrown when the client did not provide valid
+ * authentication credentials.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NotAuthenticated extends DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 401;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotFound.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotFound.php
new file mode 100644
index 0000000..210f21f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotFound.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * NotFound
+ *
+ * This Exception is thrown when a Node couldn't be found. It returns HTTP error code 404
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NotFound extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 404;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotImplemented.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotImplemented.php
new file mode 100644
index 0000000..f9624e8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/NotImplemented.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * NotImplemented
+ *
+ * This exception is thrown when the client tried to call an unsupported HTTP method or other feature
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NotImplemented extends \OldSabre\DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 501;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PaymentRequired.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PaymentRequired.php
new file mode 100644
index 0000000..1fd18be
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PaymentRequired.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * Payment Required
+ *
+ * The PaymentRequired exception may be thrown in a case where a user must pay
+ * to access a certain resource or operation.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PaymentRequired extends DAV\Exception {
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 402;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PreconditionFailed.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PreconditionFailed.php
new file mode 100644
index 0000000..625a7fc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/PreconditionFailed.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * PreconditionFailed
+ *
+ * This exception is normally thrown when a client submitted a conditional request,
+ * like for example an If, If-None-Match or If-Match header, which caused the HTTP
+ * request to not execute (the condition of the header failed)
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PreconditionFailed extends DAV\Exception {
+
+    /**
+     * When this exception is thrown, the header-name might be set.
+     *
+     * This allows the exception-catching code to determine which HTTP header
+     * caused the exception.
+     *
+     * @var string
+     */
+    public $header = null;
+
+    /**
+     * Create the exception
+     *
+     * @param string $message
+     * @param string $header
+     */
+    public function __construct($message, $header=null) {
+
+        parent::__construct($message);
+        $this->header = $header;
+
+    }
+
+    /**
+     * Returns the HTTP statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 412;
+
+    }
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        if ($this->header) {
+            $prop = $errorNode->ownerDocument->createElement('s:header');
+            $prop->nodeValue = $this->header;
+            $errorNode->appendChild($prop);
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ReportNotSupported.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ReportNotSupported.php
new file mode 100644
index 0000000..f1d42ba
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ReportNotSupported.php
@@ -0,0 +1,32 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * ReportNotSupported
+ *
+ * This exception is thrown when the client requested an unknown report through the REPORT method
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ReportNotSupported extends Forbidden {
+
+    /**
+     * This method allows the exception to include additional information into the WebDAV error response
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $error = $errorNode->ownerDocument->createElementNS('DAV:','d:supported-report');
+        $errorNode->appendChild($error);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/RequestedRangeNotSatisfiable.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/RequestedRangeNotSatisfiable.php
new file mode 100644
index 0000000..5528cde
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/RequestedRangeNotSatisfiable.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * RequestedRangeNotSatisfiable
+ *
+ * This exception is normally thrown when the user
+ * request a range that is out of the entity bounds.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class RequestedRangeNotSatisfiable extends DAV\Exception {
+
+    /**
+     * returns the http statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 416;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ServiceUnavailable.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ServiceUnavailable.php
new file mode 100644
index 0000000..94993f2
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/ServiceUnavailable.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * ServiceUnavailable
+ *
+ * This exception is thrown in case the service
+ * is currently not available (e.g. down for maintenance).
+ *
+ * @author Thomas Müller <thomas.mueller@tmit.eu>
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ServiceUnavailable extends DAV\Exception {
+
+	/**
+	 * Returns the HTTP statuscode for this exception
+	 *
+	 * @return int
+	 */
+	public function getHTTPCode() {
+
+		return 503;
+
+	}
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/UnsupportedMediaType.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/UnsupportedMediaType.php
new file mode 100644
index 0000000..32ba6f1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Exception/UnsupportedMediaType.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace OldSabre\DAV\Exception;
+
+/**
+ * UnSupportedMediaType
+ *
+ * The 415 Unsupported Media Type status code is generally sent back when the client
+ * tried to call an HTTP method, with a body the server didn't understand
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class UnsupportedMediaType extends \OldSabre\DAV\Exception {
+
+    /**
+     * returns the http statuscode for this exception
+     *
+     * @return int
+     */
+    public function getHTTPCode() {
+
+        return 415;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Directory.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Directory.php
new file mode 100644
index 0000000..a8021cc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Directory.php
@@ -0,0 +1,140 @@
+<?php
+
+namespace OldSabre\DAV\FS;
+use OldSabre\DAV;
+
+/**
+ * Directory class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Directory extends Node implements DAV\ICollection, DAV\IQuota {
+
+    /**
+     * Creates a new file in the directory
+     *
+     * Data will either be supplied as a stream resource, or in certain cases
+     * as a string. Keep in mind that you may have to support either.
+     *
+     * After successful creation of the file, you may choose to return the ETag
+     * of the new file here.
+     *
+     * The returned ETag must be surrounded by double-quotes (The quotes should
+     * be part of the actual string).
+     *
+     * If you cannot accurately determine the ETag, you should not return it.
+     * If you don't store the file exactly as-is (you're transforming it
+     * somehow) you should also not return an ETag.
+     *
+     * This means that if a subsequent GET to this new file does not exactly
+     * return the same contents of what was submitted here, you are strongly
+     * recommended to omit the ETag.
+     *
+     * @param string $name Name of the file
+     * @param resource|string $data Initial payload
+     * @return null|string
+     */
+    public function createFile($name, $data = null) {
+
+        $newPath = $this->path . '/' . $name;
+        file_put_contents($newPath,$data);
+
+    }
+
+    /**
+     * Creates a new subdirectory
+     *
+     * @param string $name
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        $newPath = $this->path . '/' . $name;
+        mkdir($newPath);
+
+    }
+
+    /**
+     * Returns a specific child node, referenced by its name
+     *
+     * This method must throw DAV\Exception\NotFound if the node does not
+     * exist.
+     *
+     * @param string $name
+     * @throws DAV\Exception\NotFound
+     * @return DAV\INode
+     */
+    public function getChild($name) {
+
+        $path = $this->path . '/' . $name;
+
+        if (!file_exists($path)) throw new DAV\Exception\NotFound('File with name ' . $path . ' could not be located');
+
+        if (is_dir($path)) {
+
+            return new Directory($path);
+
+        } else {
+
+            return new File($path);
+
+        }
+
+    }
+
+    /**
+     * Returns an array with all the child nodes
+     *
+     * @return DAV\INode[]
+     */
+    public function getChildren() {
+
+        $nodes = array();
+        foreach(scandir($this->path) as $node) if($node!='.' && $node!='..') $nodes[] = $this->getChild($node);
+        return $nodes;
+
+    }
+
+    /**
+     * Checks if a child exists.
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function childExists($name) {
+
+        $path = $this->path . '/' . $name;
+        return file_exists($path);
+
+    }
+
+    /**
+     * Deletes all files in this directory, and then itself
+     *
+     * @return void
+     */
+    public function delete() {
+
+        foreach($this->getChildren() as $child) $child->delete();
+        rmdir($this->path);
+
+    }
+
+    /**
+     * Returns available diskspace information
+     *
+     * @return array
+     */
+    public function getQuotaInfo() {
+
+        return array(
+            disk_total_space($this->path)-disk_free_space($this->path),
+            disk_free_space($this->path)
+            );
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/File.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/File.php
new file mode 100644
index 0000000..e58a705
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/File.php
@@ -0,0 +1,91 @@
+<?php
+
+namespace OldSabre\DAV\FS;
+
+use OldSabre\DAV;
+
+/**
+ * File class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class File extends Node implements DAV\IFile {
+
+    /**
+     * Updates the data
+     *
+     * @param resource $data
+     * @return void
+     */
+    public function put($data) {
+
+        file_put_contents($this->path,$data);
+
+    }
+
+    /**
+     * Returns the data
+     *
+     * @return string
+     */
+    public function get() {
+
+        return fopen($this->path,'r');
+
+    }
+
+    /**
+     * Delete the current file
+     *
+     * @return void
+     */
+    public function delete() {
+
+        unlink($this->path);
+
+    }
+
+    /**
+     * Returns the size of the node, in bytes
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        return filesize($this->path);
+
+    }
+
+    /**
+     * Returns the ETag for a file
+     *
+     * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
+     * The ETag is an arbitrary string, but MUST be surrounded by double-quotes.
+     *
+     * Return null if the ETag can not effectively be determined
+     *
+     * @return mixed
+     */
+    public function getETag() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns the mime-type for a file
+     *
+     * If null is returned, we'll assume application/octet-stream
+     *
+     * @return mixed
+     */
+    public function getContentType() {
+
+        return null;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Node.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Node.php
new file mode 100644
index 0000000..e2bf024
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FS/Node.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace OldSabre\DAV\FS;
+
+use OldSabre\DAV;
+
+/**
+ * Base node-class
+ *
+ * The node class implements the method used by both the File and the Directory classes
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Node implements DAV\INode {
+
+    /**
+     * The path to the current node
+     *
+     * @var string
+     */
+    protected $path;
+
+    /**
+     * Sets up the node, expects a full path name
+     *
+     * @param string $path
+     */
+    public function __construct($path) {
+
+        $this->path = $path;
+
+    }
+
+
+
+    /**
+     * Returns the name of the node
+     *
+     * @return string
+     */
+    public function getName() {
+
+        list(, $name)  = DAV\URLUtil::splitPath($this->path);
+        return $name;
+
+    }
+
+    /**
+     * Renames the node
+     *
+     * @param string $name The new name
+     * @return void
+     */
+    public function setName($name) {
+
+        list($parentPath, ) = DAV\URLUtil::splitPath($this->path);
+        list(, $newName) = DAV\URLUtil::splitPath($name);
+
+        $newPath = $parentPath . '/' . $newName;
+        rename($this->path,$newPath);
+
+        $this->path = $newPath;
+
+    }
+
+
+
+    /**
+     * Returns the last modification time, as a unix timestamp
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return filemtime($this->path);
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Directory.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Directory.php
new file mode 100644
index 0000000..d0e899e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Directory.php
@@ -0,0 +1,159 @@
+<?php
+
+namespace OldSabre\DAV\FSExt;
+
+use OldSabre\DAV;
+
+/**
+ * Directory class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Directory extends Node implements DAV\ICollection, DAV\IQuota {
+
+    /**
+     * Creates a new file in the directory
+     *
+     * Data will either be supplied as a stream resource, or in certain cases
+     * as a string. Keep in mind that you may have to support either.
+     *
+     * After successful creation of the file, you may choose to return the ETag
+     * of the new file here.
+     *
+     * The returned ETag must be surrounded by double-quotes (The quotes should
+     * be part of the actual string).
+     *
+     * If you cannot accurately determine the ETag, you should not return it.
+     * If you don't store the file exactly as-is (you're transforming it
+     * somehow) you should also not return an ETag.
+     *
+     * This means that if a subsequent GET to this new file does not exactly
+     * return the same contents of what was submitted here, you are strongly
+     * recommended to omit the ETag.
+     *
+     * @param string $name Name of the file
+     * @param resource|string $data Initial payload
+     * @return null|string
+     */
+    public function createFile($name, $data = null) {
+
+        // We're not allowing dots
+        if ($name=='.' || $name=='..') throw new DAV\Exception\Forbidden('Permission denied to . and ..');
+        $newPath = $this->path . '/' . $name;
+        file_put_contents($newPath,$data);
+
+        return '"' . md5_file($newPath) . '"';
+
+    }
+
+    /**
+     * Creates a new subdirectory
+     *
+     * @param string $name
+     * @return void
+     */
+    public function createDirectory($name) {
+
+        // We're not allowing dots
+        if ($name=='.' || $name=='..') throw new DAV\Exception\Forbidden('Permission denied to . and ..');
+        $newPath = $this->path . '/' . $name;
+        mkdir($newPath);
+
+    }
+
+    /**
+     * Returns a specific child node, referenced by its name
+     *
+     * This method must throw OldSabre\DAV\Exception\NotFound if the node does not
+     * exist.
+     *
+     * @param string $name
+     * @throws DAV\Exception\NotFound
+     * @return DAV\INode
+     */
+    public function getChild($name) {
+
+        $path = $this->path . '/' . $name;
+
+        if (!file_exists($path)) throw new DAV\Exception\NotFound('File could not be located');
+        if ($name=='.' || $name=='..') throw new DAV\Exception\Forbidden('Permission denied to . and ..');
+
+        if (is_dir($path)) {
+
+            return new Directory($path);
+
+        } else {
+
+            return new File($path);
+
+        }
+
+    }
+
+    /**
+     * Checks if a child exists.
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function childExists($name) {
+
+        if ($name=='.' || $name=='..')
+            throw new DAV\Exception\Forbidden('Permission denied to . and ..');
+
+        $path = $this->path . '/' . $name;
+        return file_exists($path);
+
+    }
+
+    /**
+     * Returns an array with all the child nodes
+     *
+     * @return DAV\INode[]
+     */
+    public function getChildren() {
+
+        $nodes = array();
+        foreach(scandir($this->path) as $node) if($node!='.' && $node!='..' && $node!='.sabredav') $nodes[] = $this->getChild($node);
+        return $nodes;
+
+    }
+
+    /**
+     * Deletes all files in this directory, and then itself
+     *
+     * @return bool
+     */
+    public function delete() {
+
+        // Deleting all children
+        foreach($this->getChildren() as $child) $child->delete();
+
+        // Removing resource info, if its still around
+        if (file_exists($this->path . '/.sabredav')) unlink($this->path . '/.sabredav');
+
+        // Removing the directory itself
+        rmdir($this->path);
+
+        return parent::delete();
+
+    }
+
+    /**
+     * Returns available diskspace information
+     *
+     * @return array
+     */
+    public function getQuotaInfo() {
+
+        return array(
+            disk_total_space($this->path)-disk_free_space($this->path),
+            disk_free_space($this->path)
+            );
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/File.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/File.php
new file mode 100644
index 0000000..d42e486
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/File.php
@@ -0,0 +1,146 @@
+<?php
+
+namespace OldSabre\DAV\FSExt;
+use OldSabre\DAV;
+
+/**
+ * File class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class File extends Node implements DAV\PartialUpdate\IPatchSupport {
+
+    /**
+     * Updates the data
+     *
+     * data is a readable stream resource.
+     *
+     * @param resource|string $data
+     * @return string
+     */
+    public function put($data) {
+
+        file_put_contents($this->path,$data);
+        return '"' . md5_file($this->path) . '"';
+
+    }
+
+    /**
+     * Updates the file based on a range specification.
+     *
+     * The first argument is the data, which is either a readable stream
+     * resource or a string.
+     *
+     * The second argument is the type of update we're doing.
+     * This is either:
+     * * 1. append
+     * * 2. update based on a start byte
+     * * 3. update based on an end byte
+     *;
+     * The third argument is the start or end byte.
+     *
+     * After a successful put operation, you may choose to return an ETag. The
+     * etag must always be surrounded by double-quotes. These quotes must
+     * appear in the actual string you're returning.
+     *
+     * Clients may use the ETag from a PUT request to later on make sure that
+     * when they update the file, the contents haven't changed in the mean
+     * time.
+     *
+     * @param resource|string $data
+     * @param int $rangeType
+     * @param int $offset
+     * @return string|null
+     */
+    public function patch($data, $rangeType, $offset = null) {
+
+        switch($rangeType) {
+            case 1 :
+                $f = fopen($this->path, 'a');
+                break;
+            case 2 :
+                $f = fopen($this->path, 'c');
+                fseek($f,$offset);
+                break;
+            case 3 :
+                $f = fopen($this->path, 'c');
+                fseek($f, $offset, SEEK_END);
+                break;
+        }
+        if (is_string($data)) {
+            fwrite($f, $data);
+        } else {
+            stream_copy_to_stream($data,$f);
+        }
+        fclose($f);
+        return '"' . md5_file($this->path) . '"';
+
+    }
+
+    /**
+     * Returns the data
+     *
+     * @return resource
+     */
+    public function get() {
+
+        return fopen($this->path,'r');
+
+    }
+
+    /**
+     * Delete the current file
+     *
+     * @return bool
+     */
+    public function delete() {
+
+        unlink($this->path);
+        return parent::delete();
+
+    }
+
+    /**
+     * Returns the ETag for a file
+     *
+     * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
+     * The ETag is an arbitrary string, but MUST be surrounded by double-quotes.
+     *
+     * Return null if the ETag can not effectively be determined
+     *
+     * @return string|null
+     */
+    public function getETag() {
+
+        return '"' . md5_file($this->path). '"';
+
+    }
+
+    /**
+     * Returns the mime-type for a file
+     *
+     * If null is returned, we'll assume application/octet-stream
+     *
+     * @return string|null
+     */
+    public function getContentType() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns the size of the file, in bytes
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        return filesize($this->path);
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Node.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Node.php
new file mode 100644
index 0000000..68f4255
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/FSExt/Node.php
@@ -0,0 +1,214 @@
+<?php
+
+namespace OldSabre\DAV\FSExt;
+
+use OldSabre\DAV;
+
+/**
+ * Base node-class
+ *
+ * The node class implements the method used by both the File and the Directory classes
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Node extends DAV\FS\Node implements DAV\IProperties {
+
+    /**
+     * Updates properties on this node,
+     *
+     * @param array $properties
+     * @see OldSabre\DAV\IProperties::updateProperties
+     * @return bool|array
+     */
+    public function updateProperties($properties) {
+
+        $resourceData = $this->getResourceData();
+
+        foreach($properties as $propertyName=>$propertyValue) {
+
+            // If it was null, we need to delete the property
+            if (is_null($propertyValue)) {
+                if (isset($resourceData['properties'][$propertyName])) {
+                    unset($resourceData['properties'][$propertyName]);
+                }
+            } else {
+                $resourceData['properties'][$propertyName] = $propertyValue;
+            }
+
+        }
+
+        $this->putResourceData($resourceData);
+        return true;
+    }
+
+    /**
+     * Returns a list of properties for this nodes.;
+     *
+     * The properties list is a list of propertynames the client requested, encoded as xmlnamespace#tagName, for example: http://www.example.org/namespace#author
+     * If the array is empty, all properties should be returned
+     *
+     * @param array $properties
+     * @return array
+     */
+    function getProperties($properties) {
+
+        $resourceData = $this->getResourceData();
+
+        // if the array was empty, we need to return everything
+        if (!$properties) return $resourceData['properties'];
+
+        $props = array();
+        foreach($properties as $property) {
+            if (isset($resourceData['properties'][$property])) $props[$property] = $resourceData['properties'][$property];
+        }
+
+        return $props;
+
+    }
+
+    /**
+     * Returns the path to the resource file
+     *
+     * @return string
+     */
+    protected function getResourceInfoPath() {
+
+        list($parentDir) = DAV\URLUtil::splitPath($this->path);
+        return $parentDir . '/.sabredav';
+
+    }
+
+    /**
+     * Returns all the stored resource information
+     *
+     * @return array
+     */
+    protected function getResourceData() {
+
+        $path = $this->getResourceInfoPath();
+        if (!file_exists($path)) return array('properties' => array());
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($path,'r');
+        flock($handle,LOCK_SH);
+        $data = '';
+
+        // Reading data until the eof
+        while(!feof($handle)) {
+            $data.=fread($handle,8192);
+        }
+
+        // We're all good
+        fclose($handle);
+
+        // Unserializing and checking if the resource file contains data for this file
+        $data = unserialize($data);
+        if (!isset($data[$this->getName()])) {
+            return array('properties' => array());
+        }
+
+        $data = $data[$this->getName()];
+        if (!isset($data['properties'])) $data['properties'] = array();
+        return $data;
+
+    }
+
+    /**
+     * Updates the resource information
+     *
+     * @param array $newData
+     * @return void
+     */
+    protected function putResourceData(array $newData) {
+
+        $path = $this->getResourceInfoPath();
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($path,'a+');
+        flock($handle,LOCK_EX);
+        $data = '';
+
+        rewind($handle);
+
+        // Reading data until the eof
+        while(!feof($handle)) {
+            $data.=fread($handle,8192);
+        }
+
+        // Unserializing and checking if the resource file contains data for this file
+        $data = unserialize($data);
+        $data[$this->getName()] = $newData;
+        ftruncate($handle,0);
+        rewind($handle);
+
+        fwrite($handle,serialize($data));
+        fclose($handle);
+
+    }
+
+    /**
+     * Renames the node
+     *
+     * @param string $name The new name
+     * @return void
+     */
+    public function setName($name) {
+
+        list($parentPath, ) = DAV\URLUtil::splitPath($this->path);
+        list(, $newName) = DAV\URLUtil::splitPath($name);
+        $newPath = $parentPath . '/' . $newName;
+
+        // We're deleting the existing resourcedata, and recreating it
+        // for the new path.
+        $resourceData = $this->getResourceData();
+        $this->deleteResourceData();
+
+        rename($this->path,$newPath);
+        $this->path = $newPath;
+        $this->putResourceData($resourceData);
+
+
+    }
+
+    /**
+     * @return bool
+     */
+    public function deleteResourceData() {
+
+        // When we're deleting this node, we also need to delete any resource information
+        $path = $this->getResourceInfoPath();
+        if (!file_exists($path)) return true;
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($path,'a+');
+        flock($handle,LOCK_EX);
+        $data = '';
+
+        rewind($handle);
+
+        // Reading data until the eof
+        while(!feof($handle)) {
+            $data.=fread($handle,8192);
+        }
+
+        // Unserializing and checking if the resource file contains data for this file
+        $data = unserialize($data);
+        if (isset($data[$this->getName()])) unset($data[$this->getName()]);
+        ftruncate($handle,0);
+        rewind($handle);
+        fwrite($handle,serialize($data));
+        fclose($handle);
+
+        return true;
+    }
+
+    public function delete() {
+
+        return $this->deleteResourceData();
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/File.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/File.php
new file mode 100644
index 0000000..d696eb3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/File.php
@@ -0,0 +1,85 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * File class
+ *
+ * This is a helper class, that should aid in getting file classes setup.
+ * Most of its methods are implemented, and throw permission denied exceptions
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class File extends Node implements IFile {
+
+    /**
+     * Updates the data
+     *
+     * data is a readable stream resource.
+     *
+     * @param resource $data
+     * @return void
+     */
+    public function put($data) {
+
+        throw new Exception\Forbidden('Permission denied to change data');
+
+    }
+
+    /**
+     * Returns the data
+     *
+     * This method may either return a string or a readable stream resource
+     *
+     * @return mixed
+     */
+    public function get() {
+
+        throw new Exception\Forbidden('Permission denied to read this file');
+
+    }
+
+    /**
+     * Returns the size of the file, in bytes.
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        return 0;
+
+    }
+
+    /**
+     * Returns the ETag for a file
+     *
+     * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
+     * The ETag is an arbitrary string, but MUST be surrounded by double-quotes.
+     *
+     * Return null if the ETag can not effectively be determined
+     *
+     * @return string|null
+     */
+    public function getETag() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns the mime-type for a file
+     *
+     * If null is returned, we'll assume application/octet-stream
+     *
+     * @return string|null
+     */
+    public function getContentType() {
+
+        return null;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/ICollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ICollection.php
new file mode 100644
index 0000000..0468ee1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ICollection.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * The ICollection Interface
+ *
+ * This interface should be implemented by each class that represents a collection
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface ICollection extends INode {
+
+    /**
+     * Creates a new file in the directory
+     *
+     * Data will either be supplied as a stream resource, or in certain cases
+     * as a string. Keep in mind that you may have to support either.
+     *
+     * After successful creation of the file, you may choose to return the ETag
+     * of the new file here.
+     *
+     * The returned ETag must be surrounded by double-quotes (The quotes should
+     * be part of the actual string).
+     *
+     * If you cannot accurately determine the ETag, you should not return it.
+     * If you don't store the file exactly as-is (you're transforming it
+     * somehow) you should also not return an ETag.
+     *
+     * This means that if a subsequent GET to this new file does not exactly
+     * return the same contents of what was submitted here, you are strongly
+     * recommended to omit the ETag.
+     *
+     * @param string $name Name of the file
+     * @param resource|string $data Initial payload
+     * @return null|string
+     */
+    function createFile($name, $data = null);
+
+    /**
+     * Creates a new subdirectory
+     *
+     * @param string $name
+     * @return void
+     */
+    function createDirectory($name);
+
+    /**
+     * Returns a specific child node, referenced by its name
+     *
+     * This method must throw OldSabre\DAV\Exception\NotFound if the node does not
+     * exist.
+     *
+     * @param string $name
+     * @return DAV\INode
+     */
+    function getChild($name);
+
+    /**
+     * Returns an array with all the child nodes
+     *
+     * @return DAV\INode[]
+     */
+    function getChildren();
+
+    /**
+     * Checks if a child-node with the specified name exists
+     *
+     * @param string $name
+     * @return bool
+     */
+    function childExists($name);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/IExtendedCollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IExtendedCollection.php
new file mode 100644
index 0000000..7894f58
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IExtendedCollection.php
@@ -0,0 +1,28 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * The IExtendedCollection interface.
+ *
+ * This interface can be used to create special-type of collection-resources
+ * as defined by RFC 5689.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IExtendedCollection extends ICollection {
+
+    /**
+     * Creates a new collection
+     *
+     * @param string $name
+     * @param array $resourceType
+     * @param array $properties
+     * @return void
+     */
+    function createExtendedCollection($name, array $resourceType, array $properties);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/IFile.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IFile.php
new file mode 100644
index 0000000..476ccbd
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IFile.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * This interface represents a file in the directory tree
+ *
+ * A file is a bit of a broad definition. In general it implies that on
+ * this specific node a PUT or GET method may be performed, to either update,
+ * or retrieve the contents of the file.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IFile extends INode {
+
+    /**
+     * Updates the data
+     *
+     * The data argument is a readable stream resource.
+     *
+     * After a succesful put operation, you may choose to return an ETag. The
+     * etag must always be surrounded by double-quotes. These quotes must
+     * appear in the actual string you're returning.
+     *
+     * Clients may use the ETag from a PUT request to later on make sure that
+     * when they update the file, the contents haven't changed in the mean
+     * time.
+     *
+     * If you don't plan to store the file byte-by-byte, and you return a
+     * different object on a subsequent GET you are strongly recommended to not
+     * return an ETag, and just return null.
+     *
+     * @param resource $data
+     * @return string|null
+     */
+    function put($data);
+
+    /**
+     * Returns the data
+     *
+     * This method may either return a string or a readable stream resource
+     *
+     * @return mixed
+     */
+    function get();
+
+    /**
+     * Returns the mime-type for a file
+     *
+     * If null is returned, we'll assume application/octet-stream
+     *
+     * @return string|null
+     */
+    function getContentType();
+
+    /**
+     * Returns the ETag for a file
+     *
+     * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
+     *
+     * Return null if the ETag can not effectively be determined
+     *
+     * @return void
+     */
+    function getETag();
+
+    /**
+     * Returns the size of the node, in bytes
+     *
+     * @return int
+     */
+    function getSize();
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/INode.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/INode.php
new file mode 100644
index 0000000..09c254f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/INode.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * The INode interface is the base interface, and the parent class of both ICollection and IFile
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface INode {
+
+    /**
+     * Deleted the current node
+     *
+     * @return void
+     */
+    function delete();
+
+    /**
+     * Returns the name of the node.
+     *
+     * This is used to generate the url.
+     *
+     * @return string
+     */
+    function getName();
+
+    /**
+     * Renames the node
+     *
+     * @param string $name The new name
+     * @return void
+     */
+    function setName($name);
+
+    /**
+     * Returns the last modification time, as a unix timestamp
+     *
+     * @return int
+     */
+    function getLastModified();
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/IProperties.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IProperties.php
new file mode 100644
index 0000000..8f97ebc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IProperties.php
@@ -0,0 +1,71 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * IProperties interface
+ *
+ * Implement this interface to support custom WebDAV properties requested and sent from clients.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IProperties extends INode {
+
+    /**
+     * Updates properties on this node,
+     *
+     * The properties array uses the propertyName in clark-notation as key,
+     * and the array value for the property value. In the case a property
+     * should be deleted, the property value will be null.
+     *
+     * This method must be atomic. If one property cannot be changed, the
+     * entire operation must fail.
+     *
+     * If the operation was successful, true can be returned.
+     * If the operation failed, false can be returned.
+     *
+     * Deletion of a non-existent property is always successful.
+     *
+     * Lastly, it is optional to return detailed information about any
+     * failures. In this case an array should be returned with the following
+     * structure:
+     *
+     * array(
+     *   403 => array(
+     *      '{DAV:}displayname' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}owner' => null,
+     *   )
+     * )
+     *
+     * In this example it was forbidden to update {DAV:}displayname.
+     * (403 Forbidden), which in turn also caused {DAV:}owner to fail
+     * (424 Failed Dependency) because the request needs to be atomic.
+     *
+     * @param array $mutations
+     * @return bool|array
+     */
+    function updateProperties($mutations);
+
+    /**
+     * Returns a list of properties for this nodes.
+     *
+     * The properties list is a list of propertynames the client requested,
+     * encoded in clark-notation {xmlnamespace}tagname
+     *
+     * If the array is empty, it means 'all properties' were requested.
+     *
+     * Note that it's fine to liberally give properties back, instead of
+     * conforming to the list of requested properties.
+     * The Server class will filter out the extra.
+     *
+     * @param array $properties
+     * @return void
+     */
+    function getProperties($properties);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/IQuota.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IQuota.php
new file mode 100644
index 0000000..074516e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/IQuota.php
@@ -0,0 +1,27 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * IQuota interface
+ *
+ * Implement this interface to add the ability to return quota information. The ObjectTree
+ * will check for quota information on any given node. If the information is not available it will
+ * attempt to fetch the information from the root node.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IQuota extends ICollection {
+
+    /**
+     * Returns the quota information
+     *
+     * This method MUST return an array with 2 values, the first being the total used space,
+     * the second the available space (in bytes)
+     */
+    function getQuotaInfo();
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/AbstractBackend.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/AbstractBackend.php
new file mode 100644
index 0000000..c89d37c
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/AbstractBackend.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace OldSabre\DAV\Locks\Backend;
+
+use OldSabre\DAV\Locks;
+
+/**
+ * This is an Abstract clas for lock backends.
+ *
+ * Currently this backend has no function, but it exists for consistency, and
+ * to ensure that if default code is required in the backend, there will be a
+ * non-bc-breaking way to do so.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractBackend implements BackendInterface {
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/BackendInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/BackendInterface.php
new file mode 100644
index 0000000..1a768b0
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/BackendInterface.php
@@ -0,0 +1,51 @@
+<?php
+
+namespace OldSabre\DAV\Locks\Backend;
+
+use OldSabre\DAV\Locks;
+
+/**
+ * If you are defining your own Locks backend, you must implement this
+ * interface.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface BackendInterface {
+
+    /**
+     * Returns a list of OldSabre\DAV\Locks\LockInfo objects
+     *
+     * This method should return all the locks for a particular uri, including
+     * locks that might be set on a parent uri.
+     *
+     * If returnChildLocks is set to true, this method should also look for
+     * any locks in the subtree of the uri for locks.
+     *
+     * @param string $uri
+     * @param bool $returnChildLocks
+     * @return array
+     */
+    public function getLocks($uri, $returnChildLocks);
+
+    /**
+     * Locks a uri
+     *
+     * @param string $uri
+     * @param Locks\LockInfo $lockInfo
+     * @return bool
+     */
+    public function lock($uri,Locks\LockInfo $lockInfo);
+
+    /**
+     * Removes a lock from a uri
+     *
+     * @param string $uri
+     * @param Locks\LockInfo $lockInfo
+     * @return bool
+     */
+    public function unlock($uri,Locks\LockInfo $lockInfo);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/FS.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/FS.php
new file mode 100644
index 0000000..3a61f40
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/FS.php
@@ -0,0 +1,193 @@
+<?php
+
+namespace OldSabre\DAV\Locks\Backend;
+
+use OldSabre\DAV\Locks\LockInfo;
+
+/**
+ * This Lock Backend stores all its data in the filesystem in separate file per
+ * node.
+ *
+ * This Lock Manager is now deprecated. It has a bug that allows parent
+ * collections to be deletes when children deeper in the tree are locked.
+ *
+ * This also means that using this backend means you will not pass the Neon
+ * Litmus test.
+ *
+ * You are recommended to use either the PDO or the File backend instead.
+ *
+ * @deprecated
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class FS extends AbstractBackend {
+
+    /**
+     * The default data directory
+     *
+     * @var string
+     */
+    private $dataDir;
+
+    public function __construct($dataDir) {
+
+        $this->dataDir = $dataDir;
+
+    }
+
+    protected function getFileNameForUri($uri) {
+
+        return $this->dataDir . '/sabredav_' . md5($uri) . '.locks';
+
+    }
+
+
+    /**
+     * Returns a list of OldSabre\DAV\Locks\LockInfo objects
+     *
+     * This method should return all the locks for a particular uri, including
+     * locks that might be set on a parent uri.
+     *
+     * If returnChildLocks is set to true, this method should also look for
+     * any locks in the subtree of the uri for locks.
+     *
+     * @param string $uri
+     * @param bool $returnChildLocks
+     * @return array
+     */
+    public function getLocks($uri, $returnChildLocks) {
+
+        $lockList = array();
+        $currentPath = '';
+
+        foreach(explode('/',$uri) as $uriPart) {
+
+            // weird algorithm that can probably be improved, but we're traversing the path top down
+            if ($currentPath) $currentPath.='/';
+            $currentPath.=$uriPart;
+
+            $uriLocks = $this->getData($currentPath);
+
+            foreach($uriLocks as $uriLock) {
+
+                // Unless we're on the leaf of the uri-tree we should ignore locks with depth 0
+                if($uri==$currentPath || $uriLock->depth!=0) {
+                    $uriLock->uri = $currentPath;
+                    $lockList[] = $uriLock;
+                }
+
+            }
+
+        }
+
+        // Checking if we can remove any of these locks
+        foreach($lockList as $k=>$lock) {
+            if (time() > $lock->timeout + $lock->created) unset($lockList[$k]);
+        }
+        return $lockList;
+
+    }
+
+    /**
+     * Locks a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function lock($uri, LockInfo $lockInfo) {
+
+        // We're making the lock timeout 30 minutes
+        $lockInfo->timeout = 1800;
+        $lockInfo->created = time();
+
+        $locks = $this->getLocks($uri,false);
+        foreach($locks as $k=>$lock) {
+            if ($lock->token == $lockInfo->token) unset($locks[$k]);
+        }
+        $locks[] = $lockInfo;
+        $this->putData($uri,$locks);
+        return true;
+
+    }
+
+    /**
+     * Removes a lock from a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function unlock($uri, LockInfo $lockInfo) {
+
+        $locks = $this->getLocks($uri,false);
+        foreach($locks as $k=>$lock) {
+
+            if ($lock->token == $lockInfo->token) {
+
+                unset($locks[$k]);
+                $this->putData($uri,$locks);
+                return true;
+
+            }
+        }
+        return false;
+
+    }
+
+    /**
+     * Returns the stored data for a uri
+     *
+     * @param string $uri
+     * @return array
+     */
+    protected function getData($uri) {
+
+        $path = $this->getFilenameForUri($uri);
+        if (!file_exists($path)) return array();
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($path,'r');
+        flock($handle,LOCK_SH);
+        $data = '';
+
+        // Reading data until the eof
+        while(!feof($handle)) {
+            $data.=fread($handle,8192);
+        }
+
+        // We're all good
+        fclose($handle);
+
+        // Unserializing and checking if the resource file contains data for this file
+        $data = unserialize($data);
+        if (!$data) return array();
+        return $data;
+
+    }
+
+    /**
+     * Updates the lock information
+     *
+     * @param string $uri
+     * @param array $newData
+     * @return void
+     */
+    protected function putData($uri,array $newData) {
+
+        $path = $this->getFileNameForUri($uri);
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($path,'a+');
+        flock($handle,LOCK_EX);
+        ftruncate($handle,0);
+        rewind($handle);
+
+        fwrite($handle,serialize($newData));
+        fclose($handle);
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/File.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/File.php
new file mode 100644
index 0000000..b4eb58b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/File.php
@@ -0,0 +1,183 @@
+<?php
+
+namespace OldSabre\DAV\Locks\Backend;
+
+use OldSabre\DAV\Locks\LockInfo;
+
+/**
+ * The Lock manager allows you to handle all file-locks centrally.
+ *
+ * This Lock Manager stores all its data in a single file.
+ *
+ * Note that this is not nearly as robust as a database, you are encouraged
+ * to use the PDO backend instead.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class File extends AbstractBackend {
+
+    /**
+     * The storage file
+     *
+     * @var string
+     */
+    private $locksFile;
+
+    /**
+     * Constructor
+     *
+     * @param string $locksFile path to file
+     */
+    public function __construct($locksFile) {
+
+        $this->locksFile = $locksFile;
+
+    }
+
+    /**
+     * Returns a list of OldSabre\DAV\Locks\LockInfo objects
+     *
+     * This method should return all the locks for a particular uri, including
+     * locks that might be set on a parent uri.
+     *
+     * If returnChildLocks is set to true, this method should also look for
+     * any locks in the subtree of the uri for locks.
+     *
+     * @param string $uri
+     * @param bool $returnChildLocks
+     * @return array
+     */
+    public function getLocks($uri, $returnChildLocks) {
+
+        $newLocks = array();
+
+        $locks = $this->getData();
+
+        foreach($locks as $lock) {
+
+            if ($lock->uri === $uri ||
+                //deep locks on parents
+                ($lock->depth!=0 && strpos($uri, $lock->uri . '/')===0) ||
+
+                // locks on children
+                ($returnChildLocks && (strpos($lock->uri, $uri . '/')===0)) ) {
+
+                $newLocks[] = $lock;
+
+            }
+
+        }
+
+        // Checking if we can remove any of these locks
+        foreach($newLocks as $k=>$lock) {
+            if (time() > $lock->timeout + $lock->created) unset($newLocks[$k]);
+        }
+        return $newLocks;
+
+    }
+
+    /**
+     * Locks a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function lock($uri, LockInfo $lockInfo) {
+
+        // We're making the lock timeout 30 minutes
+        $lockInfo->timeout = 1800;
+        $lockInfo->created = time();
+        $lockInfo->uri = $uri;
+
+        $locks = $this->getData();
+
+        foreach($locks as $k=>$lock) {
+            if (
+                ($lock->token == $lockInfo->token) ||
+                (time() > $lock->timeout + $lock->created)
+            ) {
+                unset($locks[$k]);
+            }
+        }
+        $locks[] = $lockInfo;
+        $this->putData($locks);
+        return true;
+
+    }
+
+    /**
+     * Removes a lock from a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function unlock($uri, LockInfo $lockInfo) {
+
+        $locks = $this->getData();
+        foreach($locks as $k=>$lock) {
+
+            if ($lock->token == $lockInfo->token) {
+
+                unset($locks[$k]);
+                $this->putData($locks);
+                return true;
+
+            }
+        }
+        return false;
+
+    }
+
+    /**
+     * Loads the lockdata from the filesystem.
+     *
+     * @return array
+     */
+    protected function getData() {
+
+        if (!file_exists($this->locksFile)) return array();
+
+        // opening up the file, and creating a shared lock
+        $handle = fopen($this->locksFile,'r');
+        flock($handle,LOCK_SH);
+
+        // Reading data until the eof
+        $data = stream_get_contents($handle);
+
+        // We're all good
+        fclose($handle);
+
+        // Unserializing and checking if the resource file contains data for this file
+        $data = unserialize($data);
+        if (!$data) return array();
+        return $data;
+
+    }
+
+    /**
+     * Saves the lockdata
+     *
+     * @param array $newData
+     * @return void
+     */
+    protected function putData(array $newData) {
+
+        // opening up the file, and creating an exclusive lock
+        $handle = fopen($this->locksFile,'a+');
+        flock($handle,LOCK_EX);
+
+        // We can only truncate and rewind once the lock is acquired.
+        ftruncate($handle,0);
+        rewind($handle);
+
+        fwrite($handle,serialize($newData));
+        fclose($handle);
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/PDO.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/PDO.php
new file mode 100644
index 0000000..520a84b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Backend/PDO.php
@@ -0,0 +1,167 @@
+<?php
+
+namespace OldSabre\DAV\Locks\Backend;
+
+use OldSabre\DAV\Locks\LockInfo;
+
+/**
+ * The Lock manager allows you to handle all file-locks centrally.
+ *
+ * This Lock Manager stores all its data in a database. You must pass a PDO
+ * connection object in the constructor.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PDO extends AbstractBackend {
+
+    /**
+     * The PDO connection object
+     *
+     * @var pdo
+     */
+    private $pdo;
+
+    /**
+     * The PDO tablename this backend uses.
+     *
+     * @var string
+     */
+    protected $tableName;
+
+    /**
+     * Constructor
+     *
+     * @param PDO $pdo
+     * @param string $tableName
+     */
+    public function __construct(\PDO $pdo, $tableName = 'locks') {
+
+        $this->pdo = $pdo;
+        $this->tableName = $tableName;
+
+    }
+
+    /**
+     * Returns a list of OldSabre\DAV\Locks\LockInfo objects
+     *
+     * This method should return all the locks for a particular uri, including
+     * locks that might be set on a parent uri.
+     *
+     * If returnChildLocks is set to true, this method should also look for
+     * any locks in the subtree of the uri for locks.
+     *
+     * @param string $uri
+     * @param bool $returnChildLocks
+     * @return array
+     */
+    public function getLocks($uri, $returnChildLocks) {
+
+        // NOTE: the following 10 lines or so could be easily replaced by
+        // pure sql. MySQL's non-standard string concatenation prevents us
+        // from doing this though.
+        $query = 'SELECT owner, token, timeout, created, scope, depth, uri FROM '.$this->tableName.' WHERE ((created + timeout) > CAST(? AS UNSIGNED INTEGER)) AND ((uri = ?)';
+        $params = array(time(),$uri);
+
+        // We need to check locks for every part in the uri.
+        $uriParts = explode('/',$uri);
+
+        // We already covered the last part of the uri
+        array_pop($uriParts);
+
+        $currentPath='';
+
+        foreach($uriParts as $part) {
+
+            if ($currentPath) $currentPath.='/';
+            $currentPath.=$part;
+
+            $query.=' OR (depth!=0 AND uri = ?)';
+            $params[] = $currentPath;
+
+        }
+
+        if ($returnChildLocks) {
+
+            $query.=' OR (uri LIKE ?)';
+            $params[] = $uri . '/%';
+
+        }
+        $query.=')';
+
+        $stmt = $this->pdo->prepare($query);
+        $stmt->execute($params);
+        $result = $stmt->fetchAll();
+
+        $lockList = array();
+        foreach($result as $row) {
+
+            $lockInfo = new LockInfo();
+            $lockInfo->owner = $row['owner'];
+            $lockInfo->token = $row['token'];
+            $lockInfo->timeout = $row['timeout'];
+            $lockInfo->created = $row['created'];
+            $lockInfo->scope = $row['scope'];
+            $lockInfo->depth = $row['depth'];
+            $lockInfo->uri   = $row['uri'];
+            $lockList[] = $lockInfo;
+
+        }
+
+        return $lockList;
+
+    }
+
+    /**
+     * Locks a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function lock($uri, LockInfo $lockInfo) {
+
+        // We're making the lock timeout 30 minutes
+        $lockInfo->timeout = 30*60;
+        $lockInfo->created = time();
+        $lockInfo->uri = $uri;
+
+        $locks = $this->getLocks($uri,false);
+        $exists = false;
+        foreach($locks as $lock) {
+            if ($lock->token == $lockInfo->token) $exists = true;
+        }
+
+        if ($exists) {
+            $stmt = $this->pdo->prepare('UPDATE '.$this->tableName.' SET owner = ?, timeout = ?, scope = ?, depth = ?, uri = ?, created = ? WHERE token = ?');
+            $stmt->execute(array($lockInfo->owner,$lockInfo->timeout,$lockInfo->scope,$lockInfo->depth,$uri,$lockInfo->created,$lockInfo->token));
+        } else {
+            $stmt = $this->pdo->prepare('INSERT INTO '.$this->tableName.' (owner,timeout,scope,depth,uri,created,token) VALUES (?,?,?,?,?,?,?)');
+            $stmt->execute(array($lockInfo->owner,$lockInfo->timeout,$lockInfo->scope,$lockInfo->depth,$uri,$lockInfo->created,$lockInfo->token));
+        }
+
+        return true;
+
+    }
+
+
+
+    /**
+     * Removes a lock from a uri
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function unlock($uri, LockInfo $lockInfo) {
+
+        $stmt = $this->pdo->prepare('DELETE FROM '.$this->tableName.' WHERE uri = ? AND token = ?');
+        $stmt->execute(array($uri,$lockInfo->token));
+
+        return $stmt->rowCount()===1;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/LockInfo.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/LockInfo.php
new file mode 100644
index 0000000..77bba97
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/LockInfo.php
@@ -0,0 +1,81 @@
+<?php
+
+namespace OldSabre\DAV\Locks;
+
+/**
+ * LockInfo class
+ *
+ * An object of the LockInfo class holds all the information relevant to a
+ * single lock.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class LockInfo {
+
+    /**
+     * A shared lock
+     */
+    const SHARED = 1;
+
+    /**
+     * An exclusive lock
+     */
+    const EXCLUSIVE = 2;
+
+    /**
+     * A never expiring timeout
+     */
+    const TIMEOUT_INFINITE = -1;
+
+    /**
+     * The owner of the lock
+     *
+     * @var string
+     */
+    public $owner;
+
+    /**
+     * The locktoken
+     *
+     * @var string
+     */
+    public $token;
+
+    /**
+     * How long till the lock is expiring
+     *
+     * @var int
+     */
+    public $timeout;
+
+    /**
+     * UNIX Timestamp of when this lock was created
+     *
+     * @var int
+     */
+    public $created;
+
+    /**
+     * Exclusive or shared lock
+     *
+     * @var int
+     */
+    public $scope = self::EXCLUSIVE;
+
+    /**
+     * Depth of lock, can be 0 or OldSabre\DAV\Server::DEPTH_INFINITY
+     */
+    public $depth = 0;
+
+    /**
+     * The uri this lock locks
+     *
+     * TODO: This value is not always set
+     * @var mixed
+     */
+    public $uri;
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Plugin.php
new file mode 100644
index 0000000..df78b92
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Locks/Plugin.php
@@ -0,0 +1,649 @@
+<?php
+
+namespace OldSabre\DAV\Locks;
+
+use OldSabre\DAV;
+
+/**
+ * Locking plugin
+ *
+ * This plugin provides locking support to a WebDAV server.
+ * The easiest way to get started, is by hooking it up as such:
+ *
+ * $lockBackend = new OldSabre\DAV\Locks\Backend\File('./mylockdb');
+ * $lockPlugin = new OldSabre\DAV\Locks\Plugin($lockBackend);
+ * $server->addPlugin($lockPlugin);
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * locksBackend
+     *
+     * @var Backend\Backend\Interface
+     */
+    protected $locksBackend;
+
+    /**
+     * server
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * __construct
+     *
+     * @param Backend\BackendInterface $locksBackend
+     */
+    public function __construct(Backend\BackendInterface $locksBackend = null) {
+
+        $this->locksBackend = $locksBackend;
+
+    }
+
+    /**
+     * Initializes the plugin
+     *
+     * This method is automatically called by the Server class after addPlugin.
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $server->subscribeEvent('unknownMethod',array($this,'unknownMethod'));
+        $server->subscribeEvent('beforeMethod',array($this,'beforeMethod'),50);
+        $server->subscribeEvent('afterGetProperties',array($this,'afterGetProperties'));
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using OldSabre\DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'locks';
+
+    }
+
+    /**
+     * This method is called by the Server if the user used an HTTP method
+     * the server didn't recognize.
+     *
+     * This plugin intercepts the LOCK and UNLOCK methods.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function unknownMethod($method, $uri) {
+
+        switch($method) {
+
+            case 'LOCK'   : $this->httpLock($uri); return false;
+            case 'UNLOCK' : $this->httpUnlock($uri); return false;
+
+        }
+
+    }
+
+    /**
+     * This method is called after most properties have been found
+     * it allows us to add in any Lock-related properties
+     *
+     * @param string $path
+     * @param array $newProperties
+     * @return bool
+     */
+    public function afterGetProperties($path, &$newProperties) {
+
+        foreach($newProperties[404] as $propName=>$discard) {
+
+            switch($propName) {
+
+                case '{DAV:}supportedlock' :
+                    $val = false;
+                    if ($this->locksBackend) $val = true;
+                    $newProperties[200][$propName] = new DAV\Property\SupportedLock($val);
+                    unset($newProperties[404][$propName]);
+                    break;
+
+                case '{DAV:}lockdiscovery' :
+                    $newProperties[200][$propName] = new DAV\Property\LockDiscovery($this->getLocks($path));
+                    unset($newProperties[404][$propName]);
+                    break;
+
+            }
+
+
+        }
+        return true;
+
+    }
+
+
+    /**
+     * This method is called before the logic for any HTTP method is
+     * handled.
+     *
+     * This plugin uses that feature to intercept access to locked resources.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        switch($method) {
+
+            case 'DELETE' :
+                $lastLock = null;
+                if (!$this->validateLock($uri,$lastLock, true))
+                    throw new DAV\Exception\Locked($lastLock);
+                break;
+            case 'MKCOL' :
+            case 'PROPPATCH' :
+            case 'PUT' :
+            case 'PATCH' :
+                $lastLock = null;
+                if (!$this->validateLock($uri,$lastLock))
+                    throw new DAV\Exception\Locked($lastLock);
+                break;
+            case 'MOVE' :
+                $lastLock = null;
+                if (!$this->validateLock(array(
+                      $uri,
+                      $this->server->calculateUri($this->server->httpRequest->getHeader('Destination')),
+                    ),$lastLock, true))
+                        throw new DAV\Exception\Locked($lastLock);
+                break;
+            case 'COPY' :
+                $lastLock = null;
+                if (!$this->validateLock(
+                      $this->server->calculateUri($this->server->httpRequest->getHeader('Destination')),
+                      $lastLock, true))
+                        throw new DAV\Exception\Locked($lastLock);
+                break;
+        }
+
+        return true;
+
+    }
+
+    /**
+     * Use this method to tell the server this plugin defines additional
+     * HTTP methods.
+     *
+     * This method is passed a uri. It should only return HTTP methods that are
+     * available for the specified uri.
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getHTTPMethods($uri) {
+
+        if ($this->locksBackend)
+            return array('LOCK','UNLOCK');
+
+        return array();
+
+    }
+
+    /**
+     * Returns a list of features for the HTTP OPTIONS Dav: header.
+     *
+     * In this case this is only the number 2. The 2 in the Dav: header
+     * indicates the server supports locks.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array(2);
+
+    }
+
+    /**
+     * Returns all lock information on a particular uri
+     *
+     * This function should return an array with OldSabre\DAV\Locks\LockInfo objects. If there are no locks on a file, return an empty array.
+     *
+     * Additionally there is also the possibility of locks on parent nodes, so we'll need to traverse every part of the tree
+     * If the $returnChildLocks argument is set to true, we'll also traverse all the children of the object
+     * for any possible locks and return those as well.
+     *
+     * @param string $uri
+     * @param bool $returnChildLocks
+     * @return array
+     */
+    public function getLocks($uri, $returnChildLocks = false) {
+
+        $lockList = array();
+
+        if ($this->locksBackend)
+            $lockList = array_merge($lockList,$this->locksBackend->getLocks($uri, $returnChildLocks));
+
+        return $lockList;
+
+    }
+
+    /**
+     * Locks an uri
+     *
+     * The WebDAV lock request can be operated to either create a new lock on a file, or to refresh an existing lock
+     * If a new lock is created, a full XML body should be supplied, containing information about the lock such as the type
+     * of lock (shared or exclusive) and the owner of the lock
+     *
+     * If a lock is to be refreshed, no body should be supplied and there should be a valid If header containing the lock
+     *
+     * Additionally, a lock can be requested for a non-existent file. In these case we're obligated to create an empty file as per RFC4918:S7.3
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpLock($uri) {
+
+        $lastLock = null;
+        if (!$this->validateLock($uri,$lastLock)) {
+
+            // If the existing lock was an exclusive lock, we need to fail
+            if (!$lastLock || $lastLock->scope == LockInfo::EXCLUSIVE) {
+                //var_dump($lastLock);
+                throw new DAV\Exception\ConflictingLock($lastLock);
+            }
+
+        }
+
+        if ($body = $this->server->httpRequest->getBody(true)) {
+            // This is a new lock request
+            $lockInfo = $this->parseLockRequest($body);
+            $lockInfo->depth = $this->server->getHTTPDepth();
+            $lockInfo->uri = $uri;
+            if($lastLock && $lockInfo->scope != LockInfo::SHARED) throw new DAV\Exception\ConflictingLock($lastLock);
+
+        } elseif ($lastLock) {
+
+            // This must have been a lock refresh
+            $lockInfo = $lastLock;
+
+            // The resource could have been locked through another uri.
+            if ($uri!=$lockInfo->uri) $uri = $lockInfo->uri;
+
+        } else {
+
+            // There was neither a lock refresh nor a new lock request
+            throw new DAV\Exception\BadRequest('An xml body is required for lock requests');
+
+        }
+
+        if ($timeout = $this->getTimeoutHeader()) $lockInfo->timeout = $timeout;
+
+        $newFile = false;
+
+        // If we got this far.. we should go check if this node actually exists. If this is not the case, we need to create it first
+        try {
+            $this->server->tree->getNodeForPath($uri);
+
+            // We need to call the beforeWriteContent event for RFC3744
+            // Edit: looks like this is not used, and causing problems now.
+            //
+            // See Issue 222
+            // $this->server->broadcastEvent('beforeWriteContent',array($uri));
+
+        } catch (DAV\Exception\NotFound $e) {
+
+            // It didn't, lets create it
+            $this->server->createFile($uri,fopen('php://memory','r'));
+            $newFile = true;
+
+        }
+
+        $this->lockNode($uri,$lockInfo);
+
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Lock-Token','<opaquelocktoken:' . $lockInfo->token . '>');
+        $this->server->httpResponse->sendStatus($newFile?201:200);
+        $this->server->httpResponse->sendBody($this->generateLockResponse($lockInfo));
+
+    }
+
+    /**
+     * Unlocks a uri
+     *
+     * This WebDAV method allows you to remove a lock from a node. The client should provide a valid locktoken through the Lock-token http header
+     * The server should return 204 (No content) on success
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpUnlock($uri) {
+
+        $lockToken = $this->server->httpRequest->getHeader('Lock-Token');
+
+        // If the locktoken header is not supplied, we need to throw a bad request exception
+        if (!$lockToken) throw new DAV\Exception\BadRequest('No lock token was supplied');
+
+        $locks = $this->getLocks($uri);
+
+        // Windows sometimes forgets to include < and > in the Lock-Token
+        // header
+        if ($lockToken[0]!=='<') $lockToken = '<' . $lockToken . '>';
+
+        foreach($locks as $lock) {
+
+            if ('<opaquelocktoken:' . $lock->token . '>' == $lockToken) {
+
+                $this->unlockNode($uri,$lock);
+                $this->server->httpResponse->setHeader('Content-Length','0');
+                $this->server->httpResponse->sendStatus(204);
+                return;
+
+            }
+
+        }
+
+        // If we got here, it means the locktoken was invalid
+        throw new DAV\Exception\LockTokenMatchesRequestUri();
+
+    }
+
+    /**
+     * Locks a uri
+     *
+     * All the locking information is supplied in the lockInfo object. The object has a suggested timeout, but this can be safely ignored
+     * It is important that if the existing timeout is ignored, the property is overwritten, as this needs to be sent back to the client
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function lockNode($uri,LockInfo $lockInfo) {
+
+        if (!$this->server->broadcastEvent('beforeLock',array($uri,$lockInfo))) return;
+
+        if ($this->locksBackend) return $this->locksBackend->lock($uri,$lockInfo);
+        throw new DAV\Exception\MethodNotAllowed('Locking support is not enabled for this resource. No Locking backend was found so if you didn\'t expect this error, please check your configuration.');
+
+    }
+
+    /**
+     * Unlocks a uri
+     *
+     * This method removes a lock from a uri. It is assumed all the supplied information is correct and verified
+     *
+     * @param string $uri
+     * @param LockInfo $lockInfo
+     * @return bool
+     */
+    public function unlockNode($uri, LockInfo $lockInfo) {
+
+        if (!$this->server->broadcastEvent('beforeUnlock',array($uri,$lockInfo))) return;
+        if ($this->locksBackend) return $this->locksBackend->unlock($uri,$lockInfo);
+
+    }
+
+
+    /**
+     * Returns the contents of the HTTP Timeout header.
+     *
+     * The method formats the header into an integer.
+     *
+     * @return int
+     */
+    public function getTimeoutHeader() {
+
+        $header = $this->server->httpRequest->getHeader('Timeout');
+
+        if ($header) {
+
+            if (stripos($header,'second-')===0) $header = (int)(substr($header,7));
+            else if (strtolower($header)=='infinite') $header = LockInfo::TIMEOUT_INFINITE;
+            else throw new DAV\Exception\BadRequest('Invalid HTTP timeout header');
+
+        } else {
+
+            $header = 0;
+
+        }
+
+        return $header;
+
+    }
+
+    /**
+     * Generates the response for successful LOCK requests
+     *
+     * @param LockInfo $lockInfo
+     * @return string
+     */
+    protected function generateLockResponse(LockInfo $lockInfo) {
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        $dom->formatOutput = true;
+
+        $prop = $dom->createElementNS('DAV:','d:prop');
+        $dom->appendChild($prop);
+
+        $lockDiscovery = $dom->createElementNS('DAV:','d:lockdiscovery');
+        $prop->appendChild($lockDiscovery);
+
+        $lockObj = new DAV\Property\LockDiscovery(array($lockInfo),true);
+        $lockObj->serialize($this->server,$lockDiscovery);
+
+        return $dom->saveXML();
+
+    }
+
+    /**
+     * validateLock should be called when a write operation is about to happen
+     * It will check if the requested url is locked, and see if the correct lock tokens are passed
+     *
+     * @param mixed $urls List of relevant urls. Can be an array, a string or nothing at all for the current request uri
+     * @param mixed $lastLock This variable will be populated with the last checked lock object (OldSabre\DAV\Locks\LockInfo)
+     * @param bool $checkChildLocks If set to true, this function will also look for any locks set on child resources of the supplied urls. This is needed for for example deletion of entire trees.
+     * @return bool
+     */
+    protected function validateLock($urls = null,&$lastLock = null, $checkChildLocks = false) {
+
+        if (is_null($urls)) {
+            $urls = array($this->server->getRequestUri());
+        } elseif (is_string($urls)) {
+            $urls = array($urls);
+        } elseif (!is_array($urls)) {
+            throw new DAV\Exception('The urls parameter should either be null, a string or an array');
+        }
+
+        $conditions = $this->getIfConditions();
+
+        // We're going to loop through the urls and make sure all lock conditions are satisfied
+        foreach($urls as $url) {
+
+            $locks = $this->getLocks($url, $checkChildLocks);
+
+            // If there were no conditions, but there were locks, we fail
+            if (!$conditions && $locks) {
+                reset($locks);
+                $lastLock = current($locks);
+                return false;
+            }
+
+            // If there were no locks or conditions, we go to the next url
+            if (!$locks && !$conditions) continue;
+
+            foreach($conditions as $condition) {
+
+                if (!$condition['uri']) {
+                    $conditionUri = $this->server->getRequestUri();
+                } else {
+                    $conditionUri = $this->server->calculateUri($condition['uri']);
+                }
+
+                // If the condition has a url, and it isn't part of the affected url at all, check the next condition
+                if ($conditionUri && strpos($url,$conditionUri)!==0) continue;
+
+                // The tokens array contians arrays with 2 elements. 0=true/false for normal/not condition, 1=locktoken
+                // At least 1 condition has to be satisfied
+                foreach($condition['tokens'] as $conditionToken) {
+
+                    $etagValid = true;
+                    $lockValid  = true;
+
+                    // key 2 can contain an etag
+                    if ($conditionToken[2]) {
+
+                        $uri = $conditionUri?$conditionUri:$this->server->getRequestUri();
+                        $node = $this->server->tree->getNodeForPath($uri);
+                        $etagValid = $node instanceof DAV\IFile && $node->getETag()==$conditionToken[2];
+
+                    }
+
+                    // key 1 can contain a lock token
+                    if ($conditionToken[1]) {
+
+                        $lockValid = false;
+                        // Match all the locks
+                        foreach($locks as $lockIndex=>$lock) {
+
+                            $lockToken = 'opaquelocktoken:' . $lock->token;
+
+                            // Checking NOT
+                            if (!$conditionToken[0] && $lockToken != $conditionToken[1]) {
+
+                                // Condition valid, onto the next
+                                $lockValid = true;
+                                break;
+                            }
+                            if ($conditionToken[0] && $lockToken == $conditionToken[1]) {
+
+                                $lastLock = $lock;
+                                // Condition valid and lock matched
+                                unset($locks[$lockIndex]);
+                                $lockValid = true;
+                                break;
+
+                            }
+
+                        }
+
+                    }
+
+                    // If, after checking both etags and locks they are stil valid,
+                    // we can continue with the next condition.
+                    if ($etagValid && $lockValid) continue 2;
+               }
+               // No conditions matched, so we fail
+               throw new DAV\Exception\PreconditionFailed('The tokens provided in the if header did not match','If');
+            }
+
+            // Conditions were met, we'll also need to check if all the locks are gone
+            if (count($locks)) {
+
+                reset($locks);
+
+                // There's still locks, we fail
+                $lastLock = current($locks);
+                return false;
+
+            }
+
+
+        }
+
+        // We got here, this means every condition was satisfied
+        return true;
+
+    }
+
+    /**
+     * This method is created to extract information from the WebDAV HTTP 'If:' header
+     *
+     * The If header can be quite complex, and has a bunch of features. We're using a regex to extract all relevant information
+     * The function will return an array, containing structs with the following keys
+     *
+     *   * uri   - the uri the condition applies to. If this is returned as an
+     *     empty string, this implies it's referring to the request url.
+     *   * tokens - The lock token. another 2 dimensional array containing 2 elements (0 = true/false.. If this is a negative condition its set to false, 1 = the actual token)
+     *   * etag - an etag, if supplied
+     *
+     * @return array
+     */
+    public function getIfConditions() {
+
+        $header = $this->server->httpRequest->getHeader('If');
+        if (!$header) return array();
+
+        $matches = array();
+
+        $regex = '/(?:\<(?P<uri>.*?)\>\s)?\((?P<not>Not\s)?(?:\<(?P<token>[^\>]*)\>)?(?:\s?)(?:\[(?P<etag>[^\]]*)\])?\)/im';
+        preg_match_all($regex,$header,$matches,PREG_SET_ORDER);
+
+        $conditions = array();
+
+        foreach($matches as $match) {
+
+            $condition = array(
+                'uri'   => $match['uri'],
+                'tokens' => array(
+                    array($match['not']?0:1,$match['token'],isset($match['etag'])?$match['etag']:'')
+                ),
+            );
+
+            if (!$condition['uri'] && count($conditions)) $conditions[count($conditions)-1]['tokens'][] = array(
+                $match['not']?0:1,
+                $match['token'],
+                isset($match['etag'])?$match['etag']:''
+            );
+            else {
+                $conditions[] = $condition;
+            }
+
+        }
+
+        return $conditions;
+
+    }
+
+    /**
+     * Parses a webdav lock xml body, and returns a new OldSabre\DAV\Locks\LockInfo object
+     *
+     * @param string $body
+     * @return DAV\Locks\LockInfo
+     */
+    protected function parseLockRequest($body) {
+
+        // Fixes an XXE vulnerability on PHP versions older than 5.3.23 or
+        // 5.4.13.
+        $previous = libxml_disable_entity_loader(true);
+
+
+        $xml = simplexml_load_string(
+            DAV\XMLUtil::convertDAVNamespace($body),
+            null,
+            LIBXML_NOWARNING);
+        libxml_disable_entity_loader($previous);
+
+        $xml->registerXPathNamespace('d','urn:DAV');
+        $lockInfo = new LockInfo();
+
+        $children = $xml->children("urn:DAV");
+        $lockInfo->owner = (string)$children->owner;
+
+        $lockInfo->token = DAV\UUIDUtil::getUUID();
+        $lockInfo->scope = count($xml->xpath('d:lockscope/d:exclusive'))>0 ? LockInfo::EXCLUSIVE : LockInfo::SHARED;
+
+        return $lockInfo;
+
+    }
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Mount/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Mount/Plugin.php
new file mode 100644
index 0000000..cfd159b
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Mount/Plugin.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace OldSabre\DAV\Mount;
+
+use OldSabre\DAV;
+
+/**
+ * This plugin provides support for RFC4709: Mounting WebDAV servers
+ *
+ * Simply append ?mount to any collection to generate the davmount response.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * Reference to Server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin and registers event handles
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $this->server->subscribeEvent('beforeMethod',array($this,'beforeMethod'), 90);
+
+    }
+
+    /**
+     * 'beforeMethod' event handles. This event handles intercepts GET requests ending
+     * with ?mount
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        if ($method!='GET') return;
+        if ($this->server->httpRequest->getQueryString()!='mount') return;
+
+        $currentUri = $this->server->httpRequest->getAbsoluteUri();
+
+        // Stripping off everything after the ?
+        list($currentUri) = explode('?',$currentUri);
+
+        $this->davMount($currentUri);
+
+        // Returning false to break the event chain
+        return false;
+
+    }
+
+    /**
+     * Generates the davmount response
+     *
+     * @param string $uri absolute uri
+     * @return void
+     */
+    public function davMount($uri) {
+
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->setHeader('Content-Type','application/davmount+xml');
+        ob_start();
+        echo '<?xml version="1.0"?>', "\n";
+        echo "<dm:mount xmlns:dm=\"http://purl.org/NET/webdav/mount\">\n";
+        echo "  <dm:url>", htmlspecialchars($uri, ENT_NOQUOTES, 'UTF-8'), "</dm:url>\n";
+        echo "</dm:mount>";
+        $this->server->httpResponse->sendBody(ob_get_clean());
+
+    }
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Node.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Node.php
new file mode 100644
index 0000000..77d7229
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Node.php
@@ -0,0 +1,55 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * Node class
+ *
+ * This is a helper class, that should aid in getting nodes setup.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Node implements INode {
+
+    /**
+     * Returns the last modification time
+     *
+     * In this case, it will simply return the current time
+     *
+     * @return int
+     */
+    public function getLastModified() {
+
+        return time();
+
+    }
+
+    /**
+     * Deletes the current node
+     *
+     * @throws OldSabre\DAV\Exception\Forbidden
+     * @return void
+     */
+    public function delete() {
+
+        throw new Exception\Forbidden('Permission denied to delete node');
+
+    }
+
+    /**
+     * Renames the node
+     *
+     * @throws OldSabre\DAV\Exception\Forbidden
+     * @param string $name The new name
+     * @return void
+     */
+    public function setName($name) {
+
+        throw new Exception\Forbidden('Permission denied to rename file');
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/ObjectTree.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ObjectTree.php
new file mode 100644
index 0000000..57057d9
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ObjectTree.php
@@ -0,0 +1,159 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * ObjectTree class
+ *
+ * This implementation of the Tree class makes use of the INode, IFile and ICollection API's
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ObjectTree extends Tree {
+
+    /**
+     * The root node
+     *
+     * @var ICollection
+     */
+    protected $rootNode;
+
+    /**
+     * This is the node cache. Accessed nodes are stored here
+     *
+     * @var array
+     */
+    protected $cache = array();
+
+    /**
+     * Creates the object
+     *
+     * This method expects the rootObject to be passed as a parameter
+     *
+     * @param ICollection $rootNode
+     */
+    public function __construct(ICollection $rootNode) {
+
+        $this->rootNode = $rootNode;
+
+    }
+
+    /**
+     * Returns the INode object for the requested path
+     *
+     * @param string $path
+     * @return INode
+     */
+    public function getNodeForPath($path) {
+
+        $path = trim($path,'/');
+        if (isset($this->cache[$path])) return $this->cache[$path];
+
+        // Is it the root node?
+        if (!strlen($path)) {
+            return $this->rootNode;
+        }
+
+        // Attempting to fetch its parent
+        list($parentName, $baseName) = URLUtil::splitPath($path);
+
+        // If there was no parent, we must simply ask it from the root node.
+        if ($parentName==="") {
+            $node = $this->rootNode->getChild($baseName);
+        } else {
+            // Otherwise, we recursively grab the parent and ask him/her.
+            $parent = $this->getNodeForPath($parentName);
+
+            if (!($parent instanceof ICollection))
+                throw new Exception\NotFound('Could not find node at path: ' . $path);
+
+            $node = $parent->getChild($baseName);
+
+        }
+
+        $this->cache[$path] = $node;
+        return $node;
+
+    }
+
+    /**
+     * This function allows you to check if a node exists.
+     *
+     * @param string $path
+     * @return bool
+     */
+    public function nodeExists($path) {
+
+        try {
+
+            // The root always exists
+            if ($path==='') return true;
+
+            list($parent, $base) = URLUtil::splitPath($path);
+
+            $parentNode = $this->getNodeForPath($parent);
+            if (!$parentNode instanceof ICollection) return false;
+            return $parentNode->childExists($base);
+
+        } catch (Exception\NotFound $e) {
+
+            return false;
+
+        }
+
+    }
+
+    /**
+     * Returns a list of childnodes for a given path.
+     *
+     * @param string $path
+     * @return array
+     */
+    public function getChildren($path) {
+
+        $node = $this->getNodeForPath($path);
+        $children = $node->getChildren();
+        foreach($children as $child) {
+
+            $this->cache[trim($path,'/') . '/' . $child->getName()] = $child;
+
+        }
+        return $children;
+
+    }
+
+    /**
+     * This method is called with every tree update
+     *
+     * Examples of tree updates are:
+     *   * node deletions
+     *   * node creations
+     *   * copy
+     *   * move
+     *   * renaming nodes
+     *
+     * If Tree classes implement a form of caching, this will allow
+     * them to make sure caches will be expired.
+     *
+     * If a path is passed, it is assumed that the entire subtree is dirty
+     *
+     * @param string $path
+     * @return void
+     */
+    public function markDirty($path) {
+
+        // We don't care enough about sub-paths
+        // flushing the entire cache
+        $path = trim($path,'/');
+        foreach($this->cache as $nodePath=>$node) {
+            if ($nodePath == $path || strpos($nodePath,$path.'/')===0)
+                unset($this->cache[$nodePath]);
+
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IFile.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IFile.php
new file mode 100644
index 0000000..2fbdf1e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IFile.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace OldSabre\DAV\PartialUpdate;
+
+use OldSabre\DAV;
+
+/**
+ * This interface is deprecated. Use IPatchSupport instead.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Jean-Tiare LE BIGOT (http://www.jtlebi.fr/)
+ * @license http://sabre.io/license/ Modified BSD License
+ * @deprecated
+ */
+interface IFile extends DAV\IFile {
+
+    /**
+     * Updates the data at a given offset
+     *
+     * The data argument is a readable stream resource.
+     * The offset argument is an integer describing the offset. Contrary to
+     * what's sent in the request, the offset here is a 0-based index.
+     *
+     * After a successful put operation, you may choose to return an ETag. The
+     * etag must always be surrounded by double-quotes. These quotes must
+     * appear in the actual string you're returning.
+     *
+     * Clients may use the ETag from a PUT request to later on make sure that
+     * when they update the file, the contents haven't changed in the mean
+     * time.
+     *
+     * @param resource $data
+     * @param integer $offset
+     * @return string|null
+     */
+    function putRange($data, $offset);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IPatchSupport.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IPatchSupport.php
new file mode 100644
index 0000000..e6e0989
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/IPatchSupport.php
@@ -0,0 +1,48 @@
+<?php
+
+namespace OldSabre\DAV\PartialUpdate;
+
+use OldSabre\DAV;
+
+/**
+ * This interface provides a way to modify only part of a target resource
+ * It may be used to update a file chunk, upload big a file into smaller
+ * chunks or resume an upload
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Jean-Tiare LE BIGOT (http://www.jtlebi.fr/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IPatchSupport extends DAV\IFile {
+
+    /**
+     * Updates the file based on a range specification.
+     *
+     * The first argument is the data, which is either a readable stream
+     * resource or a string.
+     *
+     * The second argument is the type of update we're doing.
+     * This is either:
+     * * 1. append
+     * * 2. update based on a start byte
+     * * 3. update based on an end byte
+     *;
+     * The third argument is the start or end byte.
+     *
+     * After a successful put operation, you may choose to return an ETag. The
+     * etag must always be surrounded by double-quotes. These quotes must
+     * appear in the actual string you're returning.
+     *
+     * Clients may use the ETag from a PUT request to later on make sure that
+     * when they update the file, the contents haven't changed in the mean
+     * time.
+     *
+     * @param resource|string $data
+     * @param int $rangeType
+     * @param int $offset
+     * @return string|null
+     */
+    function patch($data, $rangeType, $offset = null);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/Plugin.php
new file mode 100644
index 0000000..c1e5363
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PartialUpdate/Plugin.php
@@ -0,0 +1,246 @@
+<?php
+
+namespace OldSabre\DAV\PartialUpdate;
+
+use OldSabre\DAV;
+
+/**
+ * Partial update plugin (Patch method)
+ *
+ * This plugin provides a way to modify only part of a target resource
+ * It may bu used to update a file chunk, upload big a file into smaller
+ * chunks or resume an upload.
+ *
+ * $patchPlugin = new \OldSabre\DAV\PartialUpdate\Plugin();
+ * $server->addPlugin($patchPlugin);
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Jean-Tiare LE BIGOT (http://www.jtlebi.fr/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    const RANGE_APPEND = 1;
+    const RANGE_START = 2;
+    const RANGE_END = 3;
+
+    /**
+     * Reference to server
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * Initializes the plugin
+     *
+     * This method is automatically called by the Server class after addPlugin.
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $server->subscribeEvent('unknownMethod',array($this,'unknownMethod'));
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'partialupdate';
+
+    }
+
+    /**
+     * This method is called by the Server if the user used an HTTP method
+     * the server didn't recognize.
+     *
+     * This plugin intercepts the PATCH methods.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool|null
+     */
+    public function unknownMethod($method, $uri) {
+
+        switch($method) {
+
+            case 'PATCH':
+                return $this->httpPatch($uri);
+
+        }
+
+    }
+
+    /**
+     * Use this method to tell the server this plugin defines additional
+     * HTTP methods.
+     *
+     * This method is passed a uri. It should only return HTTP methods that are
+     * available for the specified uri.
+     *
+     * We claim to support PATCH method (partial update) if and only if
+     *     - the node exist
+     *     - the node implements our partial update interface
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getHTTPMethods($uri) {
+
+        $tree = $this->server->tree;
+        if ($tree->nodeExists($uri)) {
+            $node = $tree->getNodeForPath($uri);
+            if ($node instanceof IFile || $node instanceof IPatchSupport) {
+                return array('PATCH');
+            }
+        }
+        return array();
+
+    }
+
+    /**
+     * Returns a list of features for the HTTP OPTIONS Dav: header.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array('sabredav-partialupdate');
+
+    }
+
+    /**
+     * Patch an uri
+     *
+     * The WebDAV patch request can be used to modify only a part of an
+     * existing resource. If the resource does not exist yet and the first
+     * offset is not 0, the request fails
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpPatch($uri) {
+
+        // Get the node. Will throw a 404 if not found
+        $node = $this->server->tree->getNodeForPath($uri);
+        if (!$node instanceof IFile && !$node instanceof IPatchSupport) {
+            throw new DAV\Exception\MethodNotAllowed('The target resource does not support the PATCH method.');
+        }
+
+        $range = $this->getHTTPUpdateRange();
+
+        if (!$range) {
+            throw new DAV\Exception\BadRequest('No valid "X-Update-Range" found in the headers');
+        }
+
+        $contentType = strtolower(
+            $this->server->httpRequest->getHeader('Content-Type')
+        );
+
+        if ($contentType != 'application/x-sabredav-partialupdate') {
+            throw new DAV\Exception\UnsupportedMediaType('Unknown Content-Type header "' . $contentType . '"');
+        }
+
+        $len = $this->server->httpRequest->getHeader('Content-Length');
+        if (!$len) throw new DAV\Exception\LengthRequired('A Content-Length header is required');
+
+        switch($range[0]) {
+            case self::RANGE_START :
+                // Calculate the end-range if it doesn't exist.
+                if (!$range[2]) {
+                    $range[2] = $range[1] + $len - 1;
+                } else {
+                    if ($range[2] < $range[1]) {
+                        throw new DAV\Exception\RequestedRangeNotSatisfiable('The end offset (' . $range[2] . ') is lower than the start offset (' . $range[1] . ')');
+                    }
+                    if($range[2] - $range[1] + 1 != $len) {
+                        throw new DAV\Exception\RequestedRangeNotSatisfiable('Actual data length (' . $len . ') is not consistent with begin (' . $range[1] . ') and end (' . $range[2] . ') offsets');
+                    }
+                }
+                break;
+        }
+        // Checking If-None-Match and related headers.
+        if (!$this->server->checkPreconditions()) return;
+
+        if (!$this->server->broadcastEvent('beforeWriteContent',array($uri, $node, null)))
+            return;
+
+        $body = $this->server->httpRequest->getBody();
+
+
+        if ($node instanceof IPatchSupport) {
+            $etag = $node->patch($body, $range[0], isset($range[1])?$range[1]:null);
+        } else {
+            // The old interface
+            switch($range[0]) {
+                case self::RANGE_APPEND :
+                    throw new DAV\Exception\NotImplemented('This node does not support the append syntax. Please upgrade it to IPatchSupport');
+                case self::RANGE_START :
+                    $etag = $node->putRange($body, $range[1]);
+                    break;
+                case self::RANGE_END :
+                    throw new DAV\Exception\NotImplemented('This node does not support the end-range syntax. Please upgrade it to IPatchSupport');
+                    break;
+            }
+        }
+
+        $this->server->broadcastEvent('afterWriteContent',array($uri, $node));
+
+        $this->server->httpResponse->setHeader('Content-Length','0');
+        if ($etag) $this->server->httpResponse->setHeader('ETag',$etag);
+        $this->server->httpResponse->sendStatus(204);
+
+        return false;
+
+    }
+
+   /**
+     * Returns the HTTP custom range update header
+     *
+     * This method returns null if there is no well-formed HTTP range request
+     * header. It returns array(1) if it was an append request, array(2,
+     * $start, $end) if it's a start and end range, lastly it's array(3,
+     * $endoffset) if the offset was negative, and should be calculated from
+     * the end of the file.
+     *
+     * Examples:
+     *
+     * null - invalid
+     * array(1) - append
+     * array(2,10,15) - update bytes 10, 11, 12, 13, 14, 15
+     * array(2,10,null) - update bytes 10 until the end of the patch body
+     * array(3,-5) - update from 5 bytes from the end of the file.
+     *
+     * @return array|null
+     */
+    public function getHTTPUpdateRange() {
+
+        $range = $this->server->httpRequest->getHeader('X-Update-Range');
+        if (is_null($range)) return null;
+
+        // Matching "Range: bytes=1234-5678: both numbers are optional
+
+        if (!preg_match('/^(append)|(?:bytes=([0-9]+)-([0-9]*))|(?:bytes=(-[0-9]+))$/i',$range,$matches)) return null;
+
+        if ($matches[1]==='append') {
+            return array(self::RANGE_APPEND);
+        } elseif (strlen($matches[2])>0) {
+            return array(self::RANGE_START, $matches[2], $matches[3]?:null);
+        } elseif ($matches[4]) {
+            return array(self::RANGE_END, $matches[4]);
+        } else {
+            return null;
+        }
+
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property.php
new file mode 100644
index 0000000..88500c4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * Abstract property class
+ *
+ * Extend this class to create custom complex properties
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Property implements PropertyInterface {
+
+    /**
+     * Unserializes the property.
+     *
+     * This static method should return a an instance of this object.
+     *
+     * @param \DOMElement $prop
+     * @return DAV\IProperty
+     */
+    static function unserialize(\DOMElement $prop) {
+
+        throw new Exception('Unserialize has not been implemented for this class');
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/GetLastModified.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/GetLastModified.php
new file mode 100644
index 0000000..33f53c2
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/GetLastModified.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+use OldSabre\HTTP;
+
+/**
+ * This property represents the {DAV:}getlastmodified property.
+ *
+ * Although this is normally a simple property, windows requires us to add
+ * some new attributes.
+ *
+ * This class uses unix timestamps internally, and converts them to RFC 1123 times for
+ * serialization
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class GetLastModified extends DAV\Property {
+
+    /**
+     * time
+     *
+     * @var int
+     */
+    public $time;
+
+    /**
+     * __construct
+     *
+     * @param int|DateTime $time
+     */
+    public function __construct($time) {
+
+        if ($time instanceof \DateTime) {
+            $this->time = $time;
+        } elseif (is_int($time) || ctype_digit($time)) {
+            $this->time = new \DateTime('@' . $time);
+        } else {
+            $this->time = new \DateTime($time);
+        }
+
+        // Setting timezone to UTC
+        $this->time->setTimezone(new \DateTimeZone('UTC'));
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $prop
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $prop) {
+
+        $doc = $prop->ownerDocument;
+        //$prop->setAttribute('xmlns:b','urn:uuid:c2f41010-65b3-11d1-a29f-00aa00c14882/');
+        //$prop->setAttribute('b:dt','dateTime.rfc1123');
+        $prop->nodeValue = HTTP\Util::toHTTPDate($this->time);
+
+    }
+
+    /**
+     * getTime
+     *
+     * @return \DateTime
+     */
+    public function getTime() {
+
+        return $this->time;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Href.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Href.php
new file mode 100644
index 0000000..81f9bfb
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Href.php
@@ -0,0 +1,99 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * Href property
+ *
+ * The href property represents a url within a {DAV:}href element.
+ * This is used by many WebDAV extensions, but not really within the WebDAV core spec
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Href extends DAV\Property implements IHref {
+
+    /**
+     * href
+     *
+     * @var string
+     */
+    private $href;
+
+    /**
+     * Automatically prefix the url with the server base directory
+     *
+     * @var bool
+     */
+    private $autoPrefix = true;
+
+    /**
+     * __construct
+     *
+     * @param string $href
+     * @param bool $autoPrefix
+     */
+    public function __construct($href, $autoPrefix = true) {
+
+        $this->href = $href;
+        $this->autoPrefix = $autoPrefix;
+
+    }
+
+    /**
+     * Returns the uri
+     *
+     * @return string
+     */
+    public function getHref() {
+
+        return $this->href;
+
+    }
+
+    /**
+     * Serializes this property.
+     *
+     * It will additionally prepend the href property with the server's base uri.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $dom
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $dom) {
+
+        $prefix = $server->xmlNamespaces['DAV:'];
+        $elem = $dom->ownerDocument->createElement($prefix . ':href');
+
+        if ($this->autoPrefix) {
+            $value = $server->getBaseUri() . DAV\URLUtil::encodePath($this->href);
+        } else {
+            $value = $this->href;
+        }
+        $elem->appendChild($dom->ownerDocument->createTextNode($value));
+
+        $dom->appendChild($elem);
+
+    }
+
+    /**
+     * Unserializes this property from a DOM Element
+     *
+     * This method returns an instance of this class.
+     * It will only decode {DAV:}href values. For non-compatible elements null will be returned.
+     *
+     * @param \DOMElement $dom
+     * @return DAV\Property\Href
+     */
+    static function unserialize(\DOMElement $dom) {
+
+        if ($dom->firstChild && DAV\XMLUtil::toClarkNotation($dom->firstChild)==='{DAV:}href') {
+            return new self($dom->firstChild->textContent,false);
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/HrefList.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/HrefList.php
new file mode 100644
index 0000000..8233db1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/HrefList.php
@@ -0,0 +1,105 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * HrefList property
+ *
+ * This property contains multiple {DAV:}href elements, each containing a url.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class HrefList extends DAV\Property {
+
+    /**
+     * hrefs
+     *
+     * @var array
+     */
+    private $hrefs;
+
+    /**
+     * Automatically prefix the url with the server base directory
+     *
+     * @var bool
+     */
+    private $autoPrefix = true;
+
+    /**
+     * __construct
+     *
+     * @param array $hrefs
+     * @param bool $autoPrefix
+     */
+    public function __construct(array $hrefs, $autoPrefix = true) {
+
+        $this->hrefs = $hrefs;
+        $this->autoPrefix = $autoPrefix;
+
+    }
+
+    /**
+     * Returns the uris
+     *
+     * @return array
+     */
+    public function getHrefs() {
+
+        return $this->hrefs;
+
+    }
+
+    /**
+     * Serializes this property.
+     *
+     * It will additionally prepend the href property with the server's base uri.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $dom
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $dom) {
+
+        $prefix = $server->xmlNamespaces['DAV:'];
+
+        foreach($this->hrefs as $href) {
+
+            $elem = $dom->ownerDocument->createElement($prefix . ':href');
+            if ($this->autoPrefix) {
+                $value = $server->getBaseUri() . DAV\URLUtil::encodePath($href);
+            } else {
+                $value = $href;
+            }
+            $elem->appendChild($dom->ownerDocument->createTextNode($value));
+
+            $dom->appendChild($elem);
+        }
+
+    }
+
+    /**
+     * Unserializes this property from a DOM Element
+     *
+     * This method returns an instance of this class.
+     * It will only decode {DAV:}href values.
+     *
+     * @param \DOMElement $dom
+     * @return DAV\Property\HrefList
+     */
+    static function unserialize(\DOMElement $dom) {
+
+        $hrefs = array();
+        foreach($dom->childNodes as $child) {
+            if (DAV\XMLUtil::toClarkNotation($child)==='{DAV:}href') {
+                $hrefs[] = $child->textContent;
+            }
+        }
+        return new self($hrefs, false);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/IHref.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/IHref.php
new file mode 100644
index 0000000..ce24250
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/IHref.php
@@ -0,0 +1,25 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+/**
+ * IHref interface
+ *
+ * Any property implementing this interface can expose a related url.
+ * This is used by certain subsystems to aquire more information about for example
+ * the owner of a file
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IHref {
+
+    /**
+     * getHref
+     *
+     * @return string
+     */
+    function getHref();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/LockDiscovery.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/LockDiscovery.php
new file mode 100644
index 0000000..0a055db
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/LockDiscovery.php
@@ -0,0 +1,104 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * Represents {DAV:}lockdiscovery property
+ *
+ * This property contains all the open locks on a given resource
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class LockDiscovery extends DAV\Property {
+
+    /**
+     * locks
+     *
+     * @var array
+     */
+    public $locks;
+
+    /**
+     * Should we show the locktoken as well?
+     *
+     * @var bool
+     */
+    public $revealLockToken;
+
+    /**
+     * Hides the {DAV:}lockroot element from the response.
+     *
+     * It was reported that showing the lockroot in the response can break
+     * Office 2000 compatibility.
+     */
+    static public $hideLockRoot = false;
+
+    /**
+     * __construct
+     *
+     * @param array $locks
+     * @param bool $revealLockToken
+     */
+    public function __construct($locks, $revealLockToken = false) {
+
+        $this->locks = $locks;
+        $this->revealLockToken = $revealLockToken;
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $prop
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $prop) {
+
+        $doc = $prop->ownerDocument;
+
+        foreach($this->locks as $lock) {
+
+            $activeLock = $doc->createElementNS('DAV:','d:activelock');
+            $prop->appendChild($activeLock);
+
+            $lockScope = $doc->createElementNS('DAV:','d:lockscope');
+            $activeLock->appendChild($lockScope);
+
+            $lockScope->appendChild($doc->createElementNS('DAV:','d:' . ($lock->scope==DAV\Locks\LockInfo::EXCLUSIVE?'exclusive':'shared')));
+
+            $lockType = $doc->createElementNS('DAV:','d:locktype');
+            $activeLock->appendChild($lockType);
+
+            $lockType->appendChild($doc->createElementNS('DAV:','d:write'));
+
+            /* {DAV:}lockroot */
+            if (!self::$hideLockRoot) {
+                $lockRoot = $doc->createElementNS('DAV:','d:lockroot');
+                $activeLock->appendChild($lockRoot);
+                $href = $doc->createElementNS('DAV:','d:href');
+                $href->appendChild($doc->createTextNode($server->getBaseUri() . $lock->uri));
+                $lockRoot->appendChild($href);
+            }
+
+            $activeLock->appendChild($doc->createElementNS('DAV:','d:depth',($lock->depth == DAV\Server::DEPTH_INFINITY?'infinity':$lock->depth)));
+            $activeLock->appendChild($doc->createElementNS('DAV:','d:timeout','Second-' . $lock->timeout));
+
+            if ($this->revealLockToken) {
+                $lockToken = $doc->createElementNS('DAV:','d:locktoken');
+                $activeLock->appendChild($lockToken);
+                $lockToken->appendChild($doc->createElementNS('DAV:','d:href','opaquelocktoken:' . $lock->token));
+            }
+
+            $activeLock->appendChild($doc->createElementNS('DAV:','d:owner',$lock->owner));
+
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResourceType.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResourceType.php
new file mode 100644
index 0000000..eee2825
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResourceType.php
@@ -0,0 +1,127 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * This class represents the {DAV:}resourcetype property
+ *
+ * Normally for files this is empty, and for collection {DAV:}collection.
+ * However, other specs define different values for this.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ResourceType extends DAV\Property {
+
+    /**
+     * resourceType
+     *
+     * @var array
+     */
+    public $resourceType = array();
+
+    /**
+     * __construct
+     *
+     * @param mixed $resourceType
+     */
+    public function __construct($resourceType = array()) {
+
+        if ($resourceType === DAV\Server::NODE_FILE)
+            $this->resourceType = array();
+        elseif ($resourceType === DAV\Server::NODE_DIRECTORY)
+            $this->resourceType = array('{DAV:}collection');
+        elseif (is_array($resourceType))
+            $this->resourceType = $resourceType;
+        else
+            $this->resourceType = array($resourceType);
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $prop
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $prop) {
+
+        $propName = null;
+        $rt = $this->resourceType;
+
+        foreach($rt as $resourceType) {
+            if (preg_match('/^{([^}]*)}(.*)$/',$resourceType,$propName)) {
+
+                if (isset($server->xmlNamespaces[$propName[1]])) {
+                    $prop->appendChild($prop->ownerDocument->createElement($server->xmlNamespaces[$propName[1]] . ':' . $propName[2]));
+                } else {
+                    $prop->appendChild($prop->ownerDocument->createElementNS($propName[1],'custom:' . $propName[2]));
+                }
+
+            }
+        }
+
+    }
+
+    /**
+     * Returns the values in clark-notation
+     *
+     * For example array('{DAV:}collection')
+     *
+     * @return array
+     */
+    public function getValue() {
+
+        return $this->resourceType;
+
+    }
+
+    /**
+     * Checks if the principal contains a certain value
+     *
+     * @param string $type
+     * @return bool
+     */
+    public function is($type) {
+
+        return in_array($type, $this->resourceType);
+
+    }
+
+    /**
+     * Adds a resourcetype value to this property
+     *
+     * @param string $type
+     * @return void
+     */
+    public function add($type) {
+
+        $this->resourceType[] = $type;
+        $this->resourceType = array_unique($this->resourceType);
+
+    }
+
+    /**
+     * Unserializes a DOM element into a ResourceType property.
+     *
+     * @param \DOMElement $dom
+     * @return DAV\Property\ResourceType
+     */
+    static public function unserialize(\DOMElement $dom) {
+
+        $value = array();
+        foreach($dom->childNodes as $child) {
+
+            $value[] = DAV\XMLUtil::toClarkNotation($child);
+
+        }
+
+        return new self($value);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Response.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Response.php
new file mode 100644
index 0000000..0e1b836
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/Response.php
@@ -0,0 +1,157 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * Response property
+ *
+ * This class represents the {DAV:}response XML element.
+ * This is used by the Server class to encode individual items within a multistatus
+ * response.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Response extends DAV\Property implements IHref {
+
+    /**
+     * Url for the response
+     *
+     * @var string
+     */
+    private $href;
+
+    /**
+     * Propertylist, ordered by HTTP status code
+     *
+     * @var array
+     */
+    private $responseProperties;
+
+    /**
+     * The responseProperties argument is a list of properties
+     * within an array with keys representing HTTP status codes
+     *
+     * @param string $href
+     * @param array $responseProperties
+     */
+    public function __construct($href, array $responseProperties) {
+
+        $this->href = $href;
+        $this->responseProperties = $responseProperties;
+
+    }
+
+    /**
+     * Returns the url
+     *
+     * @return string
+     */
+    public function getHref() {
+
+        return $this->href;
+
+    }
+
+    /**
+     * Returns the property list
+     *
+     * @return array
+     */
+    public function getResponseProperties() {
+
+        return $this->responseProperties;
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $dom
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $dom) {
+
+        $document = $dom->ownerDocument;
+        $properties = $this->responseProperties;
+
+        $xresponse = $document->createElement('d:response');
+        $dom->appendChild($xresponse);
+
+        $uri = DAV\URLUtil::encodePath($this->href);
+
+        // Adding the baseurl to the beginning of the url
+        $uri = $server->getBaseUri() . $uri;
+
+        $xresponse->appendChild($document->createElement('d:href',$uri));
+
+        // The properties variable is an array containing properties, grouped by
+        // HTTP status
+        foreach($properties as $httpStatus=>$propertyGroup) {
+
+            // The 'href' is also in this array, and it's special cased.
+            // We will ignore it
+            if ($httpStatus=='href') continue;
+
+            // If there are no properties in this group, we can also just carry on
+            if (!count($propertyGroup)) continue;
+
+            $xpropstat = $document->createElement('d:propstat');
+            $xresponse->appendChild($xpropstat);
+
+            $xprop = $document->createElement('d:prop');
+            $xpropstat->appendChild($xprop);
+
+            $nsList = $server->xmlNamespaces;
+
+            foreach($propertyGroup as $propertyName=>$propertyValue) {
+
+                $propName = null;
+                preg_match('/^{([^}]*)}(.*)$/',$propertyName,$propName);
+
+                // special case for empty namespaces
+                if ($propName[1]=='') {
+
+                    $currentProperty = $document->createElement($propName[2]);
+                    $xprop->appendChild($currentProperty);
+                    $currentProperty->setAttribute('xmlns','');
+
+                } else {
+
+                    if (!isset($nsList[$propName[1]])) {
+                        $nsList[$propName[1]] = 'x' . count($nsList);
+                    }
+
+                    // If the namespace was defined in the top-level xml namespaces, it means
+                    // there was already a namespace declaration, and we don't have to worry about it.
+                    if (isset($server->xmlNamespaces[$propName[1]])) {
+                        $currentProperty = $document->createElement($nsList[$propName[1]] . ':' . $propName[2]);
+                    } else {
+                        $currentProperty = $document->createElementNS($propName[1],$nsList[$propName[1]].':' . $propName[2]);
+                    }
+                    $xprop->appendChild($currentProperty);
+
+                }
+
+                if (is_scalar($propertyValue)) {
+                    $text = $document->createTextNode($propertyValue);
+                    $currentProperty->appendChild($text);
+                } elseif ($propertyValue instanceof DAV\PropertyInterface) {
+                    $propertyValue->serialize($server,$currentProperty);
+                } elseif (!is_null($propertyValue)) {
+                    throw new DAV\Exception('Unknown property value type: ' . gettype($propertyValue) . ' for property: ' . $propertyName);
+                }
+
+            }
+
+            $xpropstat->appendChild($document->createElement('d:status',$server->httpResponse->getStatusMessage($httpStatus)));
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResponseList.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResponseList.php
new file mode 100644
index 0000000..ebf9296
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/ResponseList.php
@@ -0,0 +1,59 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * ResponseList property
+ *
+ * This class represents multiple {DAV:}response XML elements.
+ * This is used by the Server class to encode items within a multistatus
+ * response.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class ResponseList extends DAV\Property {
+
+    /**
+     * Response objects.
+     *
+     * @var array
+     */
+    private $responses;
+
+    /**
+     * The only valid argument is a list of OldSabre\DAV\Property\Response
+     * objects.
+     *
+     * @param array $responses;
+     */
+    public function __construct($responses) {
+
+        foreach($responses as $response) {
+            if (!($response instanceof Response)) {
+                throw new \InvalidArgumentException('You must pass an array of OldSabre\DAV\Property\Response objects');
+            }
+        }
+        $this->responses = $responses;
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $dom
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $dom) {
+
+        foreach($this->responses as $response) {
+            $response->serialize($server, $dom);
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedLock.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedLock.php
new file mode 100644
index 0000000..1699826
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedLock.php
@@ -0,0 +1,78 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * This class represents the {DAV:}supportedlock property
+ *
+ * This property contains information about what kind of locks
+ * this server supports.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedLock extends DAV\Property {
+
+    /**
+     * supportsLocks
+     *
+     * @var mixed
+     */
+    public $supportsLocks = false;
+
+    /**
+     * __construct
+     *
+     * @param mixed $supportsLocks
+     */
+    public function __construct($supportsLocks) {
+
+        $this->supportsLocks = $supportsLocks;
+
+    }
+
+    /**
+     * serialize
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $prop
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $prop) {
+
+        $doc = $prop->ownerDocument;
+
+        if (!$this->supportsLocks) return null;
+
+        $lockEntry1 = $doc->createElement('d:lockentry');
+        $lockEntry2 = $doc->createElement('d:lockentry');
+
+        $prop->appendChild($lockEntry1);
+        $prop->appendChild($lockEntry2);
+
+        $lockScope1 = $doc->createElement('d:lockscope');
+        $lockScope2 = $doc->createElement('d:lockscope');
+        $lockType1 = $doc->createElement('d:locktype');
+        $lockType2 = $doc->createElement('d:locktype');
+
+        $lockEntry1->appendChild($lockScope1);
+        $lockEntry1->appendChild($lockType1);
+        $lockEntry2->appendChild($lockScope2);
+        $lockEntry2->appendChild($lockType2);
+
+        $lockScope1->appendChild($doc->createElement('d:exclusive'));
+        $lockScope2->appendChild($doc->createElement('d:shared'));
+
+        $lockType1->appendChild($doc->createElement('d:write'));
+        $lockType2->appendChild($doc->createElement('d:write'));
+
+        //$frag->appendXML('<d:lockentry><d:lockscope><d:exclusive /></d:lockscope><d:locktype><d:write /></d:locktype></d:lockentry>');
+        //$frag->appendXML('<d:lockentry><d:lockscope><d:shared /></d:lockscope><d:locktype><d:write /></d:locktype></d:lockentry>');
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedReportSet.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedReportSet.php
new file mode 100644
index 0000000..ecbde7d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Property/SupportedReportSet.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace OldSabre\DAV\Property;
+
+use OldSabre\DAV;
+
+/**
+ * supported-report-set property.
+ *
+ * This property is defined in RFC3253, but since it's
+ * so common in other webdav-related specs, it is part of the core server.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedReportSet extends DAV\Property {
+
+    /**
+     * List of reports
+     *
+     * @var array
+     */
+    protected $reports = array();
+
+    /**
+     * Creates the property
+     *
+     * Any reports passed in the constructor
+     * should be valid report-types in clark-notation.
+     *
+     * Either a string or an array of strings must be passed.
+     *
+     * @param mixed $reports
+     */
+    public function __construct($reports = null) {
+
+        if (!is_null($reports))
+            $this->addReport($reports);
+
+    }
+
+    /**
+     * Adds a report to this property
+     *
+     * The report must be a string in clark-notation.
+     * Multiple reports can be specified as an array.
+     *
+     * @param mixed $report
+     * @return void
+     */
+    public function addReport($report) {
+
+        if (!is_array($report)) $report = array($report);
+
+        foreach($report as $r) {
+
+            if (!preg_match('/^{([^}]*)}(.*)$/',$r))
+                throw new DAV\Exception('Reportname must be in clark-notation');
+
+            $this->reports[] = $r;
+
+        }
+
+    }
+
+    /**
+     * Returns the list of supported reports
+     *
+     * @return array
+     */
+    public function getValue() {
+
+        return $this->reports;
+
+    }
+
+    /**
+     * Serializes the node
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $prop
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $prop) {
+
+        foreach($this->reports as $reportName) {
+
+            $supportedReport = $prop->ownerDocument->createElement('d:supported-report');
+            $prop->appendChild($supportedReport);
+
+            $report = $prop->ownerDocument->createElement('d:report');
+            $supportedReport->appendChild($report);
+
+            preg_match('/^{([^}]*)}(.*)$/',$reportName,$matches);
+
+            list(, $namespace, $element) = $matches;
+
+            $prefix = isset($server->xmlNamespaces[$namespace])?$server->xmlNamespaces[$namespace]:null;
+
+            if ($prefix) {
+                $report->appendChild($prop->ownerDocument->createElement($prefix . ':' . $element));
+            } else {
+                $report->appendChild($prop->ownerDocument->createElementNS($namespace, 'x:' . $element));
+            }
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/PropertyInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PropertyInterface.php
new file mode 100644
index 0000000..b76f94e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/PropertyInterface.php
@@ -0,0 +1,21 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * PropertyInterface
+ *
+ * Implement this interface to create new complex properties
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface PropertyInterface {
+
+    public function serialize(Server $server, \DOMElement $prop);
+
+    static function unserialize(\DOMElement $prop);
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Server.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Server.php
new file mode 100644
index 0000000..eb33f29
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Server.php
@@ -0,0 +1,2178 @@
+<?php
+
+namespace OldSabre\DAV;
+use OldSabre\HTTP;
+
+/**
+ * Main DAV server class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Server {
+
+    /**
+     * Infinity is used for some request supporting the HTTP Depth header and indicates that the operation should traverse the entire tree
+     */
+    const DEPTH_INFINITY = -1;
+
+    /**
+     * Nodes that are files, should have this as the type property
+     */
+    const NODE_FILE = 1;
+
+    /**
+     * Nodes that are directories, should use this value as the type property
+     */
+    const NODE_DIRECTORY = 2;
+
+    /**
+     * XML namespace for all SabreDAV related elements
+     */
+    const NS_SABREDAV = 'http://sabredav.org/ns';
+
+    /**
+     * The tree object
+     *
+     * @var OldSabre\DAV\Tree
+     */
+    public $tree;
+
+    /**
+     * The base uri
+     *
+     * @var string
+     */
+    protected $baseUri = null;
+
+    /**
+     * httpResponse
+     *
+     * @var OldSabre\HTTP\Response
+     */
+    public $httpResponse;
+
+    /**
+     * httpRequest
+     *
+     * @var OldSabre\HTTP\Request
+     */
+    public $httpRequest;
+
+    /**
+     * The list of plugins
+     *
+     * @var array
+     */
+    protected $plugins = array();
+
+    /**
+     * This array contains a list of callbacks we should call when certain events are triggered
+     *
+     * @var array
+     */
+    protected $eventSubscriptions = array();
+
+    /**
+     * This is a default list of namespaces.
+     *
+     * If you are defining your own custom namespace, add it here to reduce
+     * bandwidth and improve legibility of xml bodies.
+     *
+     * @var array
+     */
+    public $xmlNamespaces = array(
+        'DAV:' => 'd',
+        'http://sabredav.org/ns' => 's',
+    );
+
+    /**
+     * The propertymap can be used to map properties from
+     * requests to property classes.
+     *
+     * @var array
+     */
+    public $propertyMap = array(
+        '{DAV:}resourcetype' => 'OldSabre\\DAV\\Property\\ResourceType',
+    );
+
+    public $protectedProperties = array(
+        // RFC4918
+        '{DAV:}getcontentlength',
+        '{DAV:}getetag',
+        '{DAV:}getlastmodified',
+        '{DAV:}lockdiscovery',
+        '{DAV:}supportedlock',
+
+        // RFC4331
+        '{DAV:}quota-available-bytes',
+        '{DAV:}quota-used-bytes',
+
+        // RFC3744
+        '{DAV:}supported-privilege-set',
+        '{DAV:}current-user-privilege-set',
+        '{DAV:}acl',
+        '{DAV:}acl-restrictions',
+        '{DAV:}inherited-acl-set',
+
+    );
+
+    /**
+     * This is a flag that allow or not showing file, line and code
+     * of the exception in the returned XML
+     *
+     * @var bool
+     */
+    public $debugExceptions = false;
+
+    /**
+     * This property allows you to automatically add the 'resourcetype' value
+     * based on a node's classname or interface.
+     *
+     * The preset ensures that {DAV:}collection is automaticlly added for nodes
+     * implementing OldSabre\DAV\ICollection.
+     *
+     * @var array
+     */
+    public $resourceTypeMapping = array(
+        'OldSabre\\DAV\\ICollection' => '{DAV:}collection',
+    );
+
+    /**
+     * If this setting is turned off, SabreDAV's version number will be hidden
+     * from various places.
+     *
+     * Some people feel this is a good security measure.
+     *
+     * @var bool
+     */
+    static public $exposeVersion = true;
+
+    /**
+     * Sets up the server
+     *
+     * If a OldSabre\DAV\Tree object is passed as an argument, it will
+     * use it as the directory tree. If a OldSabre\DAV\INode is passed, it
+     * will create a OldSabre\DAV\ObjectTree and use the node as the root.
+     *
+     * If nothing is passed, a OldSabre\DAV\SimpleCollection is created in
+     * a OldSabre\DAV\ObjectTree.
+     *
+     * If an array is passed, we automatically create a root node, and use
+     * the nodes in the array as top-level children.
+     *
+     * @param Tree|INode|array|null $treeOrNode The tree object
+     */
+    public function __construct($treeOrNode = null) {
+
+        if ($treeOrNode instanceof Tree) {
+            $this->tree = $treeOrNode;
+        } elseif ($treeOrNode instanceof INode) {
+            $this->tree = new ObjectTree($treeOrNode);
+        } elseif (is_array($treeOrNode)) {
+
+            // If it's an array, a list of nodes was passed, and we need to
+            // create the root node.
+            foreach($treeOrNode as $node) {
+                if (!($node instanceof INode)) {
+                    throw new Exception('Invalid argument passed to constructor. If you\'re passing an array, all the values must implement OldSabre\\DAV\\INode');
+                }
+            }
+
+            $root = new SimpleCollection('root', $treeOrNode);
+            $this->tree = new ObjectTree($root);
+
+        } elseif (is_null($treeOrNode)) {
+            $root = new SimpleCollection('root');
+            $this->tree = new ObjectTree($root);
+        } else {
+            throw new Exception('Invalid argument passed to constructor. Argument must either be an instance of OldSabre\\DAV\\Tree, OldSabre\\DAV\\INode, an array or null');
+        }
+        $this->httpResponse = new HTTP\Response();
+        $this->httpRequest = new HTTP\Request();
+
+    }
+
+    /**
+     * Starts the DAV Server
+     *
+     * @return void
+     */
+    public function exec() {
+
+        try {
+
+            // If nginx (pre-1.2) is used as a proxy server, and SabreDAV as an
+            // origin, we must make sure we send back HTTP/1.0 if this was
+            // requested.
+            // This is mainly because nginx doesn't support Chunked Transfer
+            // Encoding, and this forces the webserver SabreDAV is running on,
+            // to buffer entire responses to calculate Content-Length.
+            $this->httpResponse->defaultHttpVersion = $this->httpRequest->getHTTPVersion();
+
+            $this->invokeMethod($this->httpRequest->getMethod(), $this->getRequestUri());
+
+        } catch (Exception $e) {
+
+            try {
+                $this->broadcastEvent('exception', array($e));
+            } catch (Exception $ignore) {
+            }
+            $DOM = new \DOMDocument('1.0','utf-8');
+            $DOM->formatOutput = true;
+
+            $error = $DOM->createElementNS('DAV:','d:error');
+            $error->setAttribute('xmlns:s',self::NS_SABREDAV);
+            $DOM->appendChild($error);
+
+            $h = function($v) {
+
+                return htmlspecialchars($v, ENT_NOQUOTES, 'UTF-8');
+
+            };
+
+            $error->appendChild($DOM->createElement('s:exception',$h(get_class($e))));
+            $error->appendChild($DOM->createElement('s:message',$h($e->getMessage())));
+            if ($this->debugExceptions) {
+                $error->appendChild($DOM->createElement('s:file',$h($e->getFile())));
+                $error->appendChild($DOM->createElement('s:line',$h($e->getLine())));
+                $error->appendChild($DOM->createElement('s:code',$h($e->getCode())));
+                $error->appendChild($DOM->createElement('s:stacktrace',$h($e->getTraceAsString())));
+
+            }
+            if (self::$exposeVersion) {
+                $error->appendChild($DOM->createElement('s:sabredav-version',$h(Version::VERSION)));
+            }
+
+            if($e instanceof Exception) {
+
+                $httpCode = $e->getHTTPCode();
+                $e->serialize($this,$error);
+                $headers = $e->getHTTPHeaders($this);
+
+            } else {
+
+                $httpCode = 500;
+                $headers = array();
+
+            }
+            $headers['Content-Type'] = 'application/xml; charset=utf-8';
+
+            $this->httpResponse->sendStatus($httpCode);
+            $this->httpResponse->setHeaders($headers);
+            $this->httpResponse->sendBody($DOM->saveXML());
+
+        }
+
+    }
+
+    /**
+     * Sets the base server uri
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function setBaseUri($uri) {
+
+        // If the baseUri does not end with a slash, we must add it
+        if ($uri[strlen($uri)-1]!=='/')
+            $uri.='/';
+
+        $this->baseUri = $uri;
+
+    }
+
+    /**
+     * Returns the base responding uri
+     *
+     * @return string
+     */
+    public function getBaseUri() {
+
+        if (is_null($this->baseUri)) $this->baseUri = $this->guessBaseUri();
+        return $this->baseUri;
+
+    }
+
+    /**
+     * This method attempts to detect the base uri.
+     * Only the PATH_INFO variable is considered.
+     *
+     * If this variable is not set, the root (/) is assumed.
+     *
+     * @return string
+     */
+    public function guessBaseUri() {
+
+        $pathInfo = $this->httpRequest->getRawServerValue('PATH_INFO');
+        $uri = $this->httpRequest->getRawServerValue('REQUEST_URI');
+
+        // If PATH_INFO is found, we can assume it's accurate.
+        if (!empty($pathInfo)) {
+
+            // We need to make sure we ignore the QUERY_STRING part
+            if ($pos = strpos($uri,'?'))
+                $uri = substr($uri,0,$pos);
+
+            // PATH_INFO is only set for urls, such as: /example.php/path
+            // in that case PATH_INFO contains '/path'.
+            // Note that REQUEST_URI is percent encoded, while PATH_INFO is
+            // not, Therefore they are only comparable if we first decode
+            // REQUEST_INFO as well.
+            $decodedUri = URLUtil::decodePath($uri);
+
+            // A simple sanity check:
+            if(substr($decodedUri,strlen($decodedUri)-strlen($pathInfo))===$pathInfo) {
+                $baseUri = substr($decodedUri,0,strlen($decodedUri)-strlen($pathInfo));
+                return rtrim($baseUri,'/') . '/';
+            }
+
+            throw new Exception('The REQUEST_URI ('. $uri . ') did not end with the contents of PATH_INFO (' . $pathInfo . '). This server might be misconfigured.');
+
+        }
+
+        // The last fallback is that we're just going to assume the server root.
+        return '/';
+
+    }
+
+    /**
+     * Adds a plugin to the server
+     *
+     * For more information, console the documentation of OldSabre\DAV\ServerPlugin
+     *
+     * @param ServerPlugin $plugin
+     * @return void
+     */
+    public function addPlugin(ServerPlugin $plugin) {
+
+        $this->plugins[$plugin->getPluginName()] = $plugin;
+        $plugin->initialize($this);
+
+    }
+
+    /**
+     * Returns an initialized plugin by it's name.
+     *
+     * This function returns null if the plugin was not found.
+     *
+     * @param string $name
+     * @return ServerPlugin
+     */
+    public function getPlugin($name) {
+
+        if (isset($this->plugins[$name]))
+            return $this->plugins[$name];
+
+        // This is a fallback and deprecated.
+        foreach($this->plugins as $plugin) {
+            if (get_class($plugin)===$name) return $plugin;
+        }
+
+        return null;
+
+    }
+
+    /**
+     * Returns all plugins
+     *
+     * @return array
+     */
+    public function getPlugins() {
+
+        return $this->plugins;
+
+    }
+
+
+    /**
+     * Subscribe to an event.
+     *
+     * When the event is triggered, we'll call all the specified callbacks.
+     * It is possible to control the order of the callbacks through the
+     * priority argument.
+     *
+     * This is for example used to make sure that the authentication plugin
+     * is triggered before anything else. If it's not needed to change this
+     * number, it is recommended to ommit.
+     *
+     * @param string $event
+     * @param callback $callback
+     * @param int $priority
+     * @return void
+     */
+    public function subscribeEvent($event, $callback, $priority = 100) {
+
+        if (!isset($this->eventSubscriptions[$event])) {
+            $this->eventSubscriptions[$event] = array();
+        }
+        while(isset($this->eventSubscriptions[$event][$priority])) $priority++;
+        $this->eventSubscriptions[$event][$priority] = $callback;
+        ksort($this->eventSubscriptions[$event]);
+
+    }
+
+    /**
+     * Broadcasts an event
+     *
+     * This method will call all subscribers. If one of the subscribers returns false, the process stops.
+     *
+     * The arguments parameter will be sent to all subscribers
+     *
+     * @param string $eventName
+     * @param array $arguments
+     * @return bool
+     */
+    public function broadcastEvent($eventName,$arguments = array()) {
+
+        if (isset($this->eventSubscriptions[$eventName])) {
+
+            foreach($this->eventSubscriptions[$eventName] as $subscriber) {
+
+                $result = call_user_func_array($subscriber,$arguments);
+                if ($result===false) return false;
+
+            }
+
+        }
+
+        return true;
+
+    }
+
+    /**
+     * Handles a http request, and execute a method based on its name
+     *
+     * @param string $method
+     * @param string $uri
+     * @return void
+     */
+    public function invokeMethod($method, $uri) {
+
+        $method = strtoupper($method);
+
+        if (!$this->broadcastEvent('beforeMethod',array($method, $uri))) return;
+
+        // Make sure this is a HTTP method we support
+        $internalMethods = array(
+            'OPTIONS',
+            'GET',
+            'HEAD',
+            'DELETE',
+            'PROPFIND',
+            'MKCOL',
+            'PUT',
+            'PROPPATCH',
+            'COPY',
+            'MOVE',
+            'REPORT'
+        );
+
+        if (in_array($method,$internalMethods)) {
+
+            call_user_func(array($this,'http' . $method), $uri);
+
+        } else {
+
+            if ($this->broadcastEvent('unknownMethod',array($method, $uri))) {
+                // Unsupported method
+                throw new Exception\NotImplemented('There was no handler found for this "' . $method . '" method');
+            }
+
+        }
+
+    }
+
+    // {{{ HTTP Method implementations
+
+    /**
+     * HTTP OPTIONS
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpOptions($uri) {
+
+        $methods = $this->getAllowedMethods($uri);
+
+        $this->httpResponse->setHeader('Allow',strtoupper(implode(', ',$methods)));
+        $features = array('1','3', 'extended-mkcol');
+
+        foreach($this->plugins as $plugin) $features = array_merge($features,$plugin->getFeatures());
+
+        $this->httpResponse->setHeader('DAV',implode(', ',$features));
+        $this->httpResponse->setHeader('MS-Author-Via','DAV');
+        $this->httpResponse->setHeader('Accept-Ranges','bytes');
+        if (self::$exposeVersion) {
+            $this->httpResponse->setHeader('X-Sabre-Version',Version::VERSION);
+        }
+        $this->httpResponse->setHeader('Content-Length',0);
+        $this->httpResponse->sendStatus(200);
+
+    }
+
+    /**
+     * HTTP GET
+     *
+     * This method simply fetches the contents of a uri, like normal
+     *
+     * @param string $uri
+     * @return bool
+     */
+    protected function httpGet($uri) {
+
+        $node = $this->tree->getNodeForPath($uri,0);
+
+        if (!$this->checkPreconditions(true)) return false;
+        if (!$node instanceof IFile) throw new Exception\NotImplemented('GET is only implemented on File objects');
+
+        $body = $node->get();
+
+        // Converting string into stream, if needed.
+        if (is_string($body)) {
+            $stream = fopen('php://temp','r+');
+            fwrite($stream,$body);
+            rewind($stream);
+            $body = $stream;
+        }
+
+        /*
+         * TODO: getetag, getlastmodified, getsize should also be used using
+         * this method
+         */
+        $httpHeaders = $this->getHTTPHeaders($uri);
+
+        /* ContentType needs to get a default, because many webservers will otherwise
+         * default to text/html, and we don't want this for security reasons.
+         */
+        if (!isset($httpHeaders['Content-Type'])) {
+            $httpHeaders['Content-Type'] = 'application/octet-stream';
+        }
+
+
+        if (isset($httpHeaders['Content-Length'])) {
+
+            $nodeSize = $httpHeaders['Content-Length'];
+
+            // Need to unset Content-Length, because we'll handle that during figuring out the range
+            unset($httpHeaders['Content-Length']);
+
+        } else {
+            $nodeSize = null;
+        }
+
+        $this->httpResponse->setHeaders($httpHeaders);
+
+        $range = $this->getHTTPRange();
+        $ifRange = $this->httpRequest->getHeader('If-Range');
+        $ignoreRangeHeader = false;
+
+        // If ifRange is set, and range is specified, we first need to check
+        // the precondition.
+        if ($nodeSize && $range && $ifRange) {
+
+            // if IfRange is parsable as a date we'll treat it as a DateTime
+            // otherwise, we must treat it as an etag.
+            try {
+                $ifRangeDate = new \DateTime($ifRange);
+
+                // It's a date. We must check if the entity is modified since
+                // the specified date.
+                if (!isset($httpHeaders['Last-Modified'])) $ignoreRangeHeader = true;
+                else {
+                    $modified = new \DateTime($httpHeaders['Last-Modified']);
+                    if($modified > $ifRangeDate) $ignoreRangeHeader = true;
+                }
+
+            } catch (\Exception $e) {
+
+                // It's an entity. We can do a simple comparison.
+                if (!isset($httpHeaders['ETag'])) $ignoreRangeHeader = true;
+                elseif ($httpHeaders['ETag']!==$ifRange) $ignoreRangeHeader = true;
+            }
+        }
+
+        // We're only going to support HTTP ranges if the backend provided a filesize
+        if (!$ignoreRangeHeader && $nodeSize && $range) {
+
+            // Determining the exact byte offsets
+            if (!is_null($range[0])) {
+
+                $start = $range[0];
+                $end = $range[1]?$range[1]:$nodeSize-1;
+                if($start >= $nodeSize)
+                    throw new Exception\RequestedRangeNotSatisfiable('The start offset (' . $range[0] . ') exceeded the size of the entity (' . $nodeSize . ')');
+
+                if($end < $start) throw new Exception\RequestedRangeNotSatisfiable('The end offset (' . $range[1] . ') is lower than the start offset (' . $range[0] . ')');
+                if($end >= $nodeSize) $end = $nodeSize-1;
+
+            } else {
+
+                $start = $nodeSize-$range[1];
+                $end  = $nodeSize-1;
+
+                if ($start<0) $start = 0;
+
+            }
+
+            // New read/write stream
+            $newStream = fopen('php://temp','r+');
+
+            // stream_copy_to_stream() has a bug/feature: the `whence` argument
+            // is interpreted as SEEK_SET (count from absolute offset 0), while
+            // for a stream it should be SEEK_CUR (count from current offset).
+            // If a stream is nonseekable, the function fails. So we *emulate*
+            // the correct behaviour with fseek():
+            if ($start > 0) {
+                if (($curOffs = ftell($body)) === false) $curOffs = 0;
+                fseek($body, $start - $curOffs, SEEK_CUR);
+            }
+            stream_copy_to_stream($body, $newStream, $end-$start+1);
+            rewind($newStream);
+
+            $this->httpResponse->setHeader('Content-Length', $end-$start+1);
+            $this->httpResponse->setHeader('Content-Range','bytes ' . $start . '-' . $end . '/' . $nodeSize);
+            $this->httpResponse->sendStatus(206);
+            $this->httpResponse->sendBody($newStream);
+
+
+        } else {
+
+            if ($nodeSize) $this->httpResponse->setHeader('Content-Length',$nodeSize);
+            $this->httpResponse->sendStatus(200);
+            $this->httpResponse->sendBody($body);
+
+        }
+
+    }
+
+    /**
+     * HTTP HEAD
+     *
+     * This method is normally used to take a peak at a url, and only get the HTTP response headers, without the body
+     * This is used by clients to determine if a remote file was changed, so they can use a local cached version, instead of downloading it again
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpHead($uri) {
+
+        $node = $this->tree->getNodeForPath($uri);
+        /* This information is only collection for File objects.
+         * Ideally we want to throw 405 Method Not Allowed for every
+         * non-file, but MS Office does not like this
+         */
+        if ($node instanceof IFile) {
+            $headers = $this->getHTTPHeaders($this->getRequestUri());
+            if (!isset($headers['Content-Type'])) {
+                $headers['Content-Type'] = 'application/octet-stream';
+            }
+            $this->httpResponse->setHeaders($headers);
+        }
+        $this->httpResponse->sendStatus(200);
+
+    }
+
+    /**
+     * HTTP Delete
+     *
+     * The HTTP delete method, deletes a given uri
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpDelete($uri) {
+
+        // Checking If-None-Match and related headers.
+        if (!$this->checkPreconditions()) return;
+
+        if (!$this->broadcastEvent('beforeUnbind',array($uri))) return;
+        $this->tree->delete($uri);
+        $this->broadcastEvent('afterUnbind',array($uri));
+
+        $this->httpResponse->sendStatus(204);
+        $this->httpResponse->setHeader('Content-Length','0');
+
+    }
+
+
+    /**
+     * WebDAV PROPFIND
+     *
+     * This WebDAV method requests information about an uri resource, or a list of resources
+     * If a client wants to receive the properties for a single resource it will add an HTTP Depth: header with a 0 value
+     * If the value is 1, it means that it also expects a list of sub-resources (e.g.: files in a directory)
+     *
+     * The request body contains an XML data structure that has a list of properties the client understands
+     * The response body is also an xml document, containing information about every uri resource and the requested properties
+     *
+     * It has to return a HTTP 207 Multi-status status code
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpPropfind($uri) {
+
+        $requestedProperties = $this->parsePropFindRequest($this->httpRequest->getBody(true));
+
+        $depth = $this->getHTTPDepth(1);
+        // The only two options for the depth of a propfind is 0 or 1
+        if ($depth!=0) $depth = 1;
+
+        $newProperties = $this->getPropertiesForPath($uri,$requestedProperties,$depth);
+
+        // This is a multi-status response
+        $this->httpResponse->sendStatus(207);
+        $this->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->httpResponse->setHeader('Vary','Brief,Prefer');
+
+        // Normally this header is only needed for OPTIONS responses, however..
+        // iCal seems to also depend on these being set for PROPFIND. Since
+        // this is not harmful, we'll add it.
+        $features = array('1','3', 'extended-mkcol');
+        foreach($this->plugins as $plugin) $features = array_merge($features,$plugin->getFeatures());
+        $this->httpResponse->setHeader('DAV',implode(', ',$features));
+
+        $prefer = $this->getHTTPPrefer();
+        $minimal = $prefer['return-minimal'];
+
+        $data = $this->generateMultiStatus($newProperties, $minimal);
+        $this->httpResponse->sendBody($data);
+
+    }
+
+    /**
+     * WebDAV PROPPATCH
+     *
+     * This method is called to update properties on a Node. The request is an XML body with all the mutations.
+     * In this XML body it is specified which properties should be set/updated and/or deleted
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpPropPatch($uri) {
+
+        $newProperties = $this->parsePropPatchRequest($this->httpRequest->getBody(true));
+
+        $result = $this->updateProperties($uri, $newProperties);
+
+        $prefer = $this->getHTTPPrefer();
+        $this->httpResponse->setHeader('Vary','Brief,Prefer');
+
+        if ($prefer['return-minimal']) {
+
+            // If return-minimal is specified, we only have to check if the
+            // request was succesful, and don't need to return the
+            // multi-status.
+            $ok = true;
+            foreach($result as $code=>$prop) {
+                if ((int)$code > 299) {
+                    $ok = false;
+                }
+            }
+
+            if ($ok) {
+
+                $this->httpResponse->sendStatus(204);
+                return;
+
+            }
+
+        }
+
+        $this->httpResponse->sendStatus(207);
+        $this->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+
+        $this->httpResponse->sendBody(
+            $this->generateMultiStatus(array($result))
+        );
+
+    }
+
+    /**
+     * HTTP PUT method
+     *
+     * This HTTP method updates a file, or creates a new one.
+     *
+     * If a new resource was created, a 201 Created status code should be returned. If an existing resource is updated, it's a 204 No Content
+     *
+     * @param string $uri
+     * @return bool
+     */
+    protected function httpPut($uri) {
+
+        $body = $this->httpRequest->getBody();
+
+        // Intercepting Content-Range
+        if ($this->httpRequest->getHeader('Content-Range')) {
+            /**
+            Content-Range is dangerous for PUT requests:  PUT per definition
+            stores a full resource.  draft-ietf-httpbis-p2-semantics-15 says
+            in section 7.6:
+              An origin server SHOULD reject any PUT request that contains a
+              Content-Range header field, since it might be misinterpreted as
+              partial content (or might be partial content that is being mistakenly
+              PUT as a full representation).  Partial content updates are possible
+              by targeting a separately identified resource with state that
+              overlaps a portion of the larger resource, or by using a different
+              method that has been specifically defined for partial updates (for
+              example, the PATCH method defined in [RFC5789]).
+            This clarifies RFC2616 section 9.6:
+              The recipient of the entity MUST NOT ignore any Content-*
+              (e.g. Content-Range) headers that it does not understand or implement
+              and MUST return a 501 (Not Implemented) response in such cases.
+            OTOH is a PUT request with a Content-Range currently the only way to
+            continue an aborted upload request and is supported by curl, mod_dav,
+            Tomcat and others.  Since some clients do use this feature which results
+            in unexpected behaviour (cf PEAR::HTTP_WebDAV_Client 1.0.1), we reject
+            all PUT requests with a Content-Range for now.
+            */
+
+            throw new Exception\NotImplemented('PUT with Content-Range is not allowed.');
+        }
+
+        // Intercepting the Finder problem
+        if (($expected = $this->httpRequest->getHeader('X-Expected-Entity-Length')) && $expected > 0) {
+
+            /**
+            Many webservers will not cooperate well with Finder PUT requests,
+            because it uses 'Chunked' transfer encoding for the request body.
+
+            The symptom of this problem is that Finder sends files to the
+            server, but they arrive as 0-length files in PHP.
+
+            If we don't do anything, the user might think they are uploading
+            files successfully, but they end up empty on the server. Instead,
+            we throw back an error if we detect this.
+
+            The reason Finder uses Chunked, is because it thinks the files
+            might change as it's being uploaded, and therefore the
+            Content-Length can vary.
+
+            Instead it sends the X-Expected-Entity-Length header with the size
+            of the file at the very start of the request. If this header is set,
+            but we don't get a request body we will fail the request to
+            protect the end-user.
+            */
+
+            // Only reading first byte
+            $firstByte = fread($body,1);
+            if (strlen($firstByte)!==1) {
+                throw new Exception\Forbidden('This server is not compatible with OS/X finder. Consider using a different WebDAV client or webserver.');
+            }
+
+            // The body needs to stay intact, so we copy everything to a
+            // temporary stream.
+
+            $newBody = fopen('php://temp','r+');
+            fwrite($newBody,$firstByte);
+            stream_copy_to_stream($body, $newBody);
+            rewind($newBody);
+
+            $body = $newBody;
+
+        }
+
+        // Checking If-None-Match and related headers.
+        if (!$this->checkPreconditions()) return;
+
+        if ($this->tree->nodeExists($uri)) {
+
+            $node = $this->tree->getNodeForPath($uri);
+
+            // If the node is a collection, we'll deny it
+            if (!($node instanceof IFile)) throw new Exception\Conflict('PUT is not allowed on non-files.');
+            if (!$this->broadcastEvent('beforeWriteContent',array($uri, $node, &$body))) return false;
+
+            $etag = $node->put($body);
+
+            $this->broadcastEvent('afterWriteContent',array($uri, $node));
+
+            $this->httpResponse->setHeader('Content-Length','0');
+            if ($etag) $this->httpResponse->setHeader('ETag',$etag);
+            $this->httpResponse->sendStatus(204);
+
+        } else {
+
+            $etag = null;
+            // If we got here, the resource didn't exist yet.
+            if (!$this->createFile($this->getRequestUri(),$body,$etag)) {
+                // For one reason or another the file was not created.
+                return;
+            }
+
+            $this->httpResponse->setHeader('Content-Length','0');
+            if ($etag) $this->httpResponse->setHeader('ETag', $etag);
+            $this->httpResponse->sendStatus(201);
+
+        }
+
+    }
+
+
+    /**
+     * WebDAV MKCOL
+     *
+     * The MKCOL method is used to create a new collection (directory) on the server
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpMkcol($uri) {
+
+        $requestBody = $this->httpRequest->getBody(true);
+
+        if ($requestBody) {
+
+            $contentType = $this->httpRequest->getHeader('Content-Type');
+            if (strpos($contentType,'application/xml')!==0 && strpos($contentType,'text/xml')!==0) {
+
+                // We must throw 415 for unsupported mkcol bodies
+                throw new Exception\UnsupportedMediaType('The request body for the MKCOL request must have an xml Content-Type');
+
+            }
+
+            $dom = XMLUtil::loadDOMDocument($requestBody);
+            if (XMLUtil::toClarkNotation($dom->firstChild)!=='{DAV:}mkcol') {
+
+                // We must throw 415 for unsupported mkcol bodies
+                throw new Exception\UnsupportedMediaType('The request body for the MKCOL request must be a {DAV:}mkcol request construct.');
+
+            }
+
+            $properties = array();
+            foreach($dom->firstChild->childNodes as $childNode) {
+
+                if (XMLUtil::toClarkNotation($childNode)!=='{DAV:}set') continue;
+                $properties = array_merge($properties, XMLUtil::parseProperties($childNode, $this->propertyMap));
+
+            }
+            if (!isset($properties['{DAV:}resourcetype']))
+                throw new Exception\BadRequest('The mkcol request must include a {DAV:}resourcetype property');
+
+            $resourceType = $properties['{DAV:}resourcetype']->getValue();
+            unset($properties['{DAV:}resourcetype']);
+
+        } else {
+
+            $properties = array();
+            $resourceType = array('{DAV:}collection');
+
+        }
+
+        $result = $this->createCollection($uri, $resourceType, $properties);
+
+        if (is_array($result)) {
+            $this->httpResponse->sendStatus(207);
+            $this->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+
+            $this->httpResponse->sendBody(
+                $this->generateMultiStatus(array($result))
+            );
+
+        } else {
+            $this->httpResponse->setHeader('Content-Length','0');
+            $this->httpResponse->sendStatus(201);
+        }
+
+    }
+
+    /**
+     * WebDAV HTTP MOVE method
+     *
+     * This method moves one uri to a different uri. A lot of the actual request processing is done in getCopyMoveInfo
+     *
+     * @param string $uri
+     * @return bool
+     */
+    protected function httpMove($uri) {
+
+        $moveInfo = $this->getCopyAndMoveInfo();
+
+        // If the destination is part of the source tree, we must fail
+        if ($moveInfo['destination']==$uri)
+            throw new Exception\Forbidden('Source and destination uri are identical.');
+
+        if ($moveInfo['destinationExists']) {
+
+            if (!$this->broadcastEvent('beforeUnbind',array($moveInfo['destination']))) return false;
+            $this->tree->delete($moveInfo['destination']);
+            $this->broadcastEvent('afterUnbind',array($moveInfo['destination']));
+
+        }
+
+        if (!$this->broadcastEvent('beforeUnbind',array($uri))) return false;
+        if (!$this->broadcastEvent('beforeBind',array($moveInfo['destination']))) return false;
+        $this->tree->move($uri,$moveInfo['destination']);
+        $this->broadcastEvent('afterUnbind',array($uri));
+        $this->broadcastEvent('afterBind',array($moveInfo['destination']));
+
+        // If a resource was overwritten we should send a 204, otherwise a 201
+        $this->httpResponse->setHeader('Content-Length','0');
+        $this->httpResponse->sendStatus($moveInfo['destinationExists']?204:201);
+
+    }
+
+    /**
+     * WebDAV HTTP COPY method
+     *
+     * This method copies one uri to a different uri, and works much like the MOVE request
+     * A lot of the actual request processing is done in getCopyMoveInfo
+     *
+     * @param string $uri
+     * @return bool
+     */
+    protected function httpCopy($uri) {
+
+        $copyInfo = $this->getCopyAndMoveInfo();
+        // If the destination is part of the source tree, we must fail
+        if ($copyInfo['destination']==$uri)
+            throw new Exception\Forbidden('Source and destination uri are identical.');
+
+        if ($copyInfo['destinationExists']) {
+            if (!$this->broadcastEvent('beforeUnbind',array($copyInfo['destination']))) return false;
+            $this->tree->delete($copyInfo['destination']);
+
+        }
+        if (!$this->broadcastEvent('beforeBind',array($copyInfo['destination']))) return false;
+        $this->tree->copy($uri,$copyInfo['destination']);
+        $this->broadcastEvent('afterBind',array($copyInfo['destination']));
+
+        // If a resource was overwritten we should send a 204, otherwise a 201
+        $this->httpResponse->setHeader('Content-Length','0');
+        $this->httpResponse->sendStatus($copyInfo['destinationExists']?204:201);
+
+    }
+
+
+
+    /**
+     * HTTP REPORT method implementation
+     *
+     * Although the REPORT method is not part of the standard WebDAV spec (it's from rfc3253)
+     * It's used in a lot of extensions, so it made sense to implement it into the core.
+     *
+     * @param string $uri
+     * @return void
+     */
+    protected function httpReport($uri) {
+
+        $body = $this->httpRequest->getBody(true);
+        $dom = XMLUtil::loadDOMDocument($body);
+
+        $reportName = XMLUtil::toClarkNotation($dom->firstChild);
+
+        if ($this->broadcastEvent('report',array($reportName,$dom, $uri))) {
+
+            // If broadcastEvent returned true, it means the report was not supported
+            throw new Exception\ReportNotSupported();
+
+        }
+
+    }
+
+    // }}}
+    // {{{ HTTP/WebDAV protocol helpers
+
+    /**
+     * Returns an array with all the supported HTTP methods for a specific uri.
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getAllowedMethods($uri) {
+
+        $methods = array(
+            'OPTIONS',
+            'GET',
+            'HEAD',
+            'DELETE',
+            'PROPFIND',
+            'PUT',
+            'PROPPATCH',
+            'COPY',
+            'MOVE',
+            'REPORT'
+        );
+
+        // The MKCOL is only allowed on an unmapped uri
+        try {
+            $this->tree->getNodeForPath($uri);
+        } catch (Exception\NotFound $e) {
+            $methods[] = 'MKCOL';
+        }
+
+        // We're also checking if any of the plugins register any new methods
+        foreach($this->plugins as $plugin) $methods = array_merge($methods, $plugin->getHTTPMethods($uri));
+        array_unique($methods);
+
+        return $methods;
+
+    }
+
+    /**
+     * Gets the uri for the request, keeping the base uri into consideration
+     *
+     * @return string
+     */
+    public function getRequestUri() {
+
+        return $this->calculateUri($this->httpRequest->getUri());
+
+    }
+
+    /**
+     * Calculates the uri for a request, making sure that the base uri is stripped out
+     *
+     * @param string $uri
+     * @throws Exception\Forbidden A permission denied exception is thrown whenever there was an attempt to supply a uri outside of the base uri
+     * @return string
+     */
+    public function calculateUri($uri) {
+
+        if ($uri[0]!='/' && strpos($uri,'://')) {
+
+            $uri = parse_url($uri,PHP_URL_PATH);
+
+        }
+
+        $uri = str_replace('//','/',$uri);
+
+        if (strpos($uri,$this->getBaseUri())===0) {
+
+            return trim(URLUtil::decodePath(substr($uri,strlen($this->getBaseUri()))),'/');
+
+        // A special case, if the baseUri was accessed without a trailing
+        // slash, we'll accept it as well.
+        } elseif ($uri.'/' === $this->getBaseUri()) {
+
+            return '';
+
+        } else {
+
+            throw new Exception\Forbidden('Requested uri (' . $uri . ') is out of base uri (' . $this->getBaseUri() . ')');
+
+        }
+
+    }
+
+    /**
+     * Returns the HTTP depth header
+     *
+     * This method returns the contents of the HTTP depth request header. If the depth header was 'infinity' it will return the OldSabre\DAV\Server::DEPTH_INFINITY object
+     * It is possible to supply a default depth value, which is used when the depth header has invalid content, or is completely non-existent
+     *
+     * @param mixed $default
+     * @return int
+     */
+    public function getHTTPDepth($default = self::DEPTH_INFINITY) {
+
+        // If its not set, we'll grab the default
+        $depth = $this->httpRequest->getHeader('Depth');
+
+        if (is_null($depth)) return $default;
+
+        if ($depth == 'infinity') return self::DEPTH_INFINITY;
+
+
+        // If its an unknown value. we'll grab the default
+        if (!ctype_digit($depth)) return $default;
+
+        return (int)$depth;
+
+    }
+
+    /**
+     * Returns the HTTP range header
+     *
+     * This method returns null if there is no well-formed HTTP range request
+     * header or array($start, $end).
+     *
+     * The first number is the offset of the first byte in the range.
+     * The second number is the offset of the last byte in the range.
+     *
+     * If the second offset is null, it should be treated as the offset of the last byte of the entity
+     * If the first offset is null, the second offset should be used to retrieve the last x bytes of the entity
+     *
+     * @return array|null
+     */
+    public function getHTTPRange() {
+
+        $range = $this->httpRequest->getHeader('range');
+        if (is_null($range)) return null;
+
+        // Matching "Range: bytes=1234-5678: both numbers are optional
+
+        if (!preg_match('/^bytes=([0-9]*)-([0-9]*)$/i',$range,$matches)) return null;
+
+        if ($matches[1]==='' && $matches[2]==='') return null;
+
+        return array(
+            $matches[1]!==''?$matches[1]:null,
+            $matches[2]!==''?$matches[2]:null,
+        );
+
+    }
+
+    /**
+     * Returns the HTTP Prefer header information.
+     *
+     * The prefer header is defined in:
+     * http://tools.ietf.org/html/draft-snell-http-prefer-14
+     *
+     * This method will return an array with options.
+     *
+     * Currently, the following options may be returned:
+     *   array(
+     *      'return-asynch'         => true,
+     *      'return-minimal'        => true,
+     *      'return-representation' => true,
+     *      'wait'                  => 30,
+     *      'strict'                => true,
+     *      'lenient'               => true,
+     *   )
+     *
+     * This method also supports the Brief header, and will also return
+     * 'return-minimal' if the brief header was set to 't'.
+     *
+     * For the boolean options, false will be returned if the headers are not
+     * specified. For the integer options it will be 'null'.
+     *
+     * @return array
+     */
+    public function getHTTPPrefer() {
+
+        $result = array(
+            'return-asynch'         => false,
+            'return-minimal'        => false,
+            'return-representation' => false,
+            'wait'                  => null,
+            'strict'                => false,
+            'lenient'               => false,
+        );
+
+        if ($prefer = $this->httpRequest->getHeader('Prefer')) {
+
+            $parameters = array_map('trim',
+                explode(',', $prefer)
+            );
+
+            foreach($parameters as $parameter) {
+
+                // Right now our regex only supports the tokens actually
+                // specified in the draft. We may need to expand this if new
+                // tokens get registered.
+                if(!preg_match('/^(?P<token>[a-z0-9-]+)(?:=(?P<value>[0-9]+))?$/', $parameter, $matches)) {
+                    continue;
+                }
+
+                switch($matches['token']) {
+
+                    case 'return-asynch' :
+                    case 'return-minimal' :
+                    case 'return-representation' :
+                    case 'strict' :
+                    case 'lenient' :
+                        $result[$matches['token']] = true;
+                        break;
+                    case 'wait' :
+                        $result[$matches['token']] = $matches['value'];
+                        break;
+
+                }
+
+            }
+
+        }
+
+        if ($this->httpRequest->getHeader('Brief')=='t') {
+            $result['return-minimal'] = true;
+        }
+
+        return $result;
+
+    }
+
+
+    /**
+     * Returns information about Copy and Move requests
+     *
+     * This function is created to help getting information about the source and the destination for the
+     * WebDAV MOVE and COPY HTTP request. It also validates a lot of information and throws proper exceptions
+     *
+     * The returned value is an array with the following keys:
+     *   * destination - Destination path
+     *   * destinationExists - Whether or not the destination is an existing url (and should therefore be overwritten)
+     *
+     * @return array
+     */
+    public function getCopyAndMoveInfo() {
+
+        // Collecting the relevant HTTP headers
+        if (!$this->httpRequest->getHeader('Destination')) throw new Exception\BadRequest('The destination header was not supplied');
+        $destination = $this->calculateUri($this->httpRequest->getHeader('Destination'));
+        $overwrite = $this->httpRequest->getHeader('Overwrite');
+        if (!$overwrite) $overwrite = 'T';
+        if (strtoupper($overwrite)=='T') $overwrite = true;
+        elseif (strtoupper($overwrite)=='F') $overwrite = false;
+        // We need to throw a bad request exception, if the header was invalid
+        else throw new Exception\BadRequest('The HTTP Overwrite header should be either T or F');
+
+        list($destinationDir) = URLUtil::splitPath($destination);
+
+        try {
+            $destinationParent = $this->tree->getNodeForPath($destinationDir);
+            if (!($destinationParent instanceof ICollection)) throw new Exception\UnsupportedMediaType('The destination node is not a collection');
+        } catch (Exception\NotFound $e) {
+
+            // If the destination parent node is not found, we throw a 409
+            throw new Exception\Conflict('The destination node is not found');
+        }
+
+        try {
+
+            $destinationNode = $this->tree->getNodeForPath($destination);
+
+            // If this succeeded, it means the destination already exists
+            // we'll need to throw precondition failed in case overwrite is false
+            if (!$overwrite) throw new Exception\PreconditionFailed('The destination node already exists, and the overwrite header is set to false','Overwrite');
+
+        } catch (Exception\NotFound $e) {
+
+            // Destination didn't exist, we're all good
+            $destinationNode = false;
+
+
+
+        }
+
+        // These are the three relevant properties we need to return
+        return array(
+            'destination'       => $destination,
+            'destinationExists' => $destinationNode==true,
+            'destinationNode'   => $destinationNode,
+        );
+
+    }
+
+    /**
+     * Returns a list of properties for a path
+     *
+     * This is a simplified version getPropertiesForPath.
+     * if you aren't interested in status codes, but you just
+     * want to have a flat list of properties. Use this method.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     */
+    public function getProperties($path, $propertyNames) {
+
+        $result = $this->getPropertiesForPath($path,$propertyNames,0);
+        return $result[0][200];
+
+    }
+
+    /**
+     * A kid-friendly way to fetch properties for a node's children.
+     *
+     * The returned array will be indexed by the path of the of child node.
+     * Only properties that are actually found will be returned.
+     *
+     * The parent node will not be returned.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     * @return array
+     */
+    public function getPropertiesForChildren($path, $propertyNames) {
+
+        $result = array();
+        foreach($this->getPropertiesForPath($path,$propertyNames,1) as $k=>$row) {
+
+            // Skipping the parent path
+            if ($k === 0) continue;
+
+            $result[$row['href']] = $row[200];
+
+        }
+        return $result;
+
+    }
+
+    /**
+     * Returns a list of HTTP headers for a particular resource
+     *
+     * The generated http headers are based on properties provided by the
+     * resource. The method basically provides a simple mapping between
+     * DAV property and HTTP header.
+     *
+     * The headers are intended to be used for HEAD and GET requests.
+     *
+     * @param string $path
+     * @return array
+     */
+    public function getHTTPHeaders($path) {
+
+        $propertyMap = array(
+            '{DAV:}getcontenttype'   => 'Content-Type',
+            '{DAV:}getcontentlength' => 'Content-Length',
+            '{DAV:}getlastmodified'  => 'Last-Modified',
+            '{DAV:}getetag'          => 'ETag',
+        );
+
+        $properties = $this->getProperties($path,array_keys($propertyMap));
+
+        $headers = array();
+        foreach($propertyMap as $property=>$header) {
+            if (!isset($properties[$property])) continue;
+
+            if (is_scalar($properties[$property])) {
+                $headers[$header] = $properties[$property];
+
+            // GetLastModified gets special cased
+            } elseif ($properties[$property] instanceof Property\GetLastModified) {
+                $headers[$header] = HTTP\Util::toHTTPDate($properties[$property]->getTime());
+            }
+
+        }
+
+        return $headers;
+
+    }
+
+    /**
+     * Returns a list of properties for a given path
+     *
+     * The path that should be supplied should have the baseUrl stripped out
+     * The list of properties should be supplied in Clark notation. If the list is empty
+     * 'allprops' is assumed.
+     *
+     * If a depth of 1 is requested child elements will also be returned.
+     *
+     * @param string $path
+     * @param array $propertyNames
+     * @param int $depth
+     * @return array
+     */
+    public function getPropertiesForPath($path, $propertyNames = array(), $depth = 0) {
+
+        if ($depth!=0) $depth = 1;
+
+        $path = rtrim($path,'/');
+
+        // This event allows people to intercept these requests early on in the
+        // process.
+        //
+        // We're not doing anything with the result, but this can be helpful to
+        // pre-fetch certain expensive live properties.
+        $this->broadCastEvent('beforeGetPropertiesForPath', array($path, $propertyNames, $depth));
+
+        $returnPropertyList = array();
+
+        $parentNode = $this->tree->getNodeForPath($path);
+        $nodes = array(
+            $path => $parentNode
+        );
+        if ($depth==1 && $parentNode instanceof ICollection) {
+            foreach($this->tree->getChildren($path) as $childNode)
+                $nodes[$path . '/' . $childNode->getName()] = $childNode;
+        }
+
+        // If the propertyNames array is empty, it means all properties are requested.
+        // We shouldn't actually return everything we know though, and only return a
+        // sensible list.
+        $allProperties = count($propertyNames)==0;
+
+        foreach($nodes as $myPath=>$node) {
+
+            $currentPropertyNames = $propertyNames;
+
+            $newProperties = array(
+                '200' => array(),
+                '404' => array(),
+            );
+
+            if ($allProperties) {
+                // Default list of propertyNames, when all properties were requested.
+                $currentPropertyNames = array(
+                    '{DAV:}getlastmodified',
+                    '{DAV:}getcontentlength',
+                    '{DAV:}resourcetype',
+                    '{DAV:}quota-used-bytes',
+                    '{DAV:}quota-available-bytes',
+                    '{DAV:}getetag',
+                    '{DAV:}getcontenttype',
+                );
+            }
+
+            // If the resourceType was not part of the list, we manually add it
+            // and mark it for removal. We need to know the resourcetype in order
+            // to make certain decisions about the entry.
+            // WebDAV dictates we should add a / and the end of href's for collections
+            $removeRT = false;
+            if (!in_array('{DAV:}resourcetype',$currentPropertyNames)) {
+                $currentPropertyNames[] = '{DAV:}resourcetype';
+                $removeRT = true;
+            }
+
+            $result = $this->broadcastEvent('beforeGetProperties',array($myPath, $node, &$currentPropertyNames, &$newProperties));
+            // If this method explicitly returned false, we must ignore this
+            // node as it is inaccessible.
+            if ($result===false) continue;
+
+            if (count($currentPropertyNames) > 0) {
+
+                if ($node instanceof IProperties) {
+                    $nodeProperties = $node->getProperties($currentPropertyNames);
+
+                    // The getProperties method may give us too much,
+                    // properties, in case the implementor was lazy.
+                    //
+                    // So as we loop through this list, we will only take the
+                    // properties that were actually requested and discard the
+                    // rest.
+                    foreach($currentPropertyNames as $k=>$currentPropertyName) {
+                        if (isset($nodeProperties[$currentPropertyName])) {
+                            unset($currentPropertyNames[$k]);
+                            $newProperties[200][$currentPropertyName] = $nodeProperties[$currentPropertyName];
+                        }
+                    }
+
+                }
+
+            }
+
+            foreach($currentPropertyNames as $prop) {
+
+                if (isset($newProperties[200][$prop])) continue;
+
+                switch($prop) {
+                    case '{DAV:}getlastmodified'       : if ($node->getLastModified()) $newProperties[200][$prop] = new Property\GetLastModified($node->getLastModified()); break;
+                    case '{DAV:}getcontentlength'      :
+                        if ($node instanceof IFile) {
+                            $size = $node->getSize();
+                            if (!is_null($size)) {
+                                $newProperties[200][$prop] = (int)$node->getSize();
+                            }
+                        }
+                        break;
+                    case '{DAV:}quota-used-bytes'      :
+                        if ($node instanceof IQuota) {
+                            $quotaInfo = $node->getQuotaInfo();
+                            $newProperties[200][$prop] = $quotaInfo[0];
+                        }
+                        break;
+                    case '{DAV:}quota-available-bytes' :
+                        if ($node instanceof IQuota) {
+                            $quotaInfo = $node->getQuotaInfo();
+                            $newProperties[200][$prop] = $quotaInfo[1];
+                        }
+                        break;
+                    case '{DAV:}getetag'               : if ($node instanceof IFile && $etag = $node->getETag())  $newProperties[200][$prop] = $etag; break;
+                    case '{DAV:}getcontenttype'        : if ($node instanceof IFile && $ct = $node->getContentType())  $newProperties[200][$prop] = $ct; break;
+                    case '{DAV:}supported-report-set'  :
+                        $reports = array();
+                        foreach($this->plugins as $plugin) {
+                            $reports = array_merge($reports, $plugin->getSupportedReportSet($myPath));
+                        }
+                        $newProperties[200][$prop] = new Property\SupportedReportSet($reports);
+                        break;
+                    case '{DAV:}resourcetype' :
+                        $newProperties[200]['{DAV:}resourcetype'] = new Property\ResourceType();
+                        foreach($this->resourceTypeMapping as $className => $resourceType) {
+                            if ($node instanceof $className) $newProperties[200]['{DAV:}resourcetype']->add($resourceType);
+                        }
+                        break;
+
+                }
+
+                // If we were unable to find the property, we will list it as 404.
+                if (!$allProperties && !isset($newProperties[200][$prop])) $newProperties[404][$prop] = null;
+
+            }
+
+            $this->broadcastEvent('afterGetProperties',array(trim($myPath,'/'),&$newProperties, $node));
+
+            $newProperties['href'] = trim($myPath,'/');
+
+            // Its is a WebDAV recommendation to add a trailing slash to collectionnames.
+            // Apple's iCal also requires a trailing slash for principals (rfc 3744), though this is non-standard.
+            if ($myPath!='' && isset($newProperties[200]['{DAV:}resourcetype'])) {
+                $rt = $newProperties[200]['{DAV:}resourcetype'];
+                if ($rt->is('{DAV:}collection') || $rt->is('{DAV:}principal')) {
+                    $newProperties['href'] .='/';
+                }
+            }
+
+            // If the resourcetype property was manually added to the requested property list,
+            // we will remove it again.
+            if ($removeRT) unset($newProperties[200]['{DAV:}resourcetype']);
+
+            $returnPropertyList[] = $newProperties;
+
+        }
+
+        return $returnPropertyList;
+
+    }
+
+    /**
+     * This method is invoked by sub-systems creating a new file.
+     *
+     * Currently this is done by HTTP PUT and HTTP LOCK (in the Locks_Plugin).
+     * It was important to get this done through a centralized function,
+     * allowing plugins to intercept this using the beforeCreateFile event.
+     *
+     * This method will return true if the file was actually created
+     *
+     * @param string   $uri
+     * @param resource $data
+     * @param string   $etag
+     * @return bool
+     */
+    public function createFile($uri,$data, &$etag = null) {
+
+        list($dir,$name) = URLUtil::splitPath($uri);
+
+        if (!$this->broadcastEvent('beforeBind',array($uri))) return false;
+
+        $parent = $this->tree->getNodeForPath($dir);
+        if (!$parent instanceof ICollection) {
+            throw new Exception\Conflict('Files can only be created as children of collections');
+        }
+
+        if (!$this->broadcastEvent('beforeCreateFile',array($uri, &$data, $parent))) return false;
+
+        $etag = $parent->createFile($name,$data);
+        $this->tree->markDirty($dir . '/' . $name);
+
+        $this->broadcastEvent('afterBind',array($uri));
+        $this->broadcastEvent('afterCreateFile',array($uri, $parent));
+
+        return true;
+    }
+
+    /**
+     * This method is invoked by sub-systems creating a new directory.
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function createDirectory($uri) {
+
+        $this->createCollection($uri,array('{DAV:}collection'),array());
+
+    }
+
+    /**
+     * Use this method to create a new collection
+     *
+     * The {DAV:}resourcetype is specified using the resourceType array.
+     * At the very least it must contain {DAV:}collection.
+     *
+     * The properties array can contain a list of additional properties.
+     *
+     * @param string $uri The new uri
+     * @param array $resourceType The resourceType(s)
+     * @param array $properties A list of properties
+     * @return array|null
+     */
+    public function createCollection($uri, array $resourceType, array $properties) {
+
+        list($parentUri,$newName) = URLUtil::splitPath($uri);
+
+        // Making sure {DAV:}collection was specified as resourceType
+        if (!in_array('{DAV:}collection', $resourceType)) {
+            throw new Exception\InvalidResourceType('The resourceType for this collection must at least include {DAV:}collection');
+        }
+
+
+        // Making sure the parent exists
+        try {
+
+            $parent = $this->tree->getNodeForPath($parentUri);
+
+        } catch (Exception\NotFound $e) {
+
+            throw new Exception\Conflict('Parent node does not exist');
+
+        }
+
+        // Making sure the parent is a collection
+        if (!$parent instanceof ICollection) {
+            throw new Exception\Conflict('Parent node is not a collection');
+        }
+
+
+
+        // Making sure the child does not already exist
+        try {
+            $parent->getChild($newName);
+
+            // If we got here.. it means there's already a node on that url, and we need to throw a 405
+            throw new Exception\MethodNotAllowed('The resource you tried to create already exists');
+
+        } catch (Exception\NotFound $e) {
+            // This is correct
+        }
+
+
+        if (!$this->broadcastEvent('beforeBind',array($uri))) return;
+
+        // There are 2 modes of operation. The standard collection
+        // creates the directory, and then updates properties
+        // the extended collection can create it directly.
+        if ($parent instanceof IExtendedCollection) {
+
+            $parent->createExtendedCollection($newName, $resourceType, $properties);
+
+        } else {
+
+            // No special resourcetypes are supported
+            if (count($resourceType)>1) {
+                throw new Exception\InvalidResourceType('The {DAV:}resourcetype you specified is not supported here.');
+            }
+
+            $parent->createDirectory($newName);
+            $rollBack = false;
+            $exception = null;
+            $errorResult = null;
+
+            if (count($properties)>0) {
+
+                try {
+
+                    $errorResult = $this->updateProperties($uri, $properties);
+                    if (!isset($errorResult[200])) {
+                        $rollBack = true;
+                    }
+
+                } catch (Exception $e) {
+
+                    $rollBack = true;
+                    $exception = $e;
+
+                }
+
+            }
+
+            if ($rollBack) {
+                if (!$this->broadcastEvent('beforeUnbind',array($uri))) return;
+                $this->tree->delete($uri);
+
+                // Re-throwing exception
+                if ($exception) throw $exception;
+
+                return $errorResult;
+            }
+
+        }
+        $this->tree->markDirty($parentUri);
+        $this->broadcastEvent('afterBind',array($uri));
+
+    }
+
+    /**
+     * This method updates a resource's properties
+     *
+     * The properties array must be a list of properties. Array-keys are
+     * property names in clarknotation, array-values are it's values.
+     * If a property must be deleted, the value should be null.
+     *
+     * Note that this request should either completely succeed, or
+     * completely fail.
+     *
+     * The response is an array with statuscodes for keys, which in turn
+     * contain arrays with propertynames. This response can be used
+     * to generate a multistatus body.
+     *
+     * @param string $uri
+     * @param array $properties
+     * @return array
+     */
+    public function updateProperties($uri, array $properties) {
+
+        // we'll start by grabbing the node, this will throw the appropriate
+        // exceptions if it doesn't.
+        $node = $this->tree->getNodeForPath($uri);
+
+        $result = array(
+            200 => array(),
+            403 => array(),
+            424 => array(),
+        );
+        $remainingProperties = $properties;
+        $hasError = false;
+
+        // Running through all properties to make sure none of them are protected
+        if (!$hasError) foreach($properties as $propertyName => $value) {
+            if(in_array($propertyName, $this->protectedProperties)) {
+                $result[403][$propertyName] = null;
+                unset($remainingProperties[$propertyName]);
+                $hasError = true;
+            }
+        }
+
+        if (!$hasError) {
+            // Allowing plugins to take care of property updating
+            $hasError = !$this->broadcastEvent('updateProperties',array(
+                &$remainingProperties,
+                &$result,
+                $node
+            ));
+        }
+
+        // If the node is not an instance of OldSabre\DAV\IProperties, every
+        // property is 403 Forbidden
+        if (!$hasError && count($remainingProperties) && !($node instanceof IProperties)) {
+            $hasError = true;
+            foreach($properties as $propertyName=> $value) {
+                $result[403][$propertyName] = null;
+            }
+            $remainingProperties = array();
+        }
+
+        // Only if there were no errors we may attempt to update the resource
+        if (!$hasError) {
+
+            if (count($remainingProperties)>0) {
+
+                $updateResult = $node->updateProperties($remainingProperties);
+
+                if ($updateResult===true) {
+                    // success
+                    foreach($remainingProperties as $propertyName=>$value) {
+                        $result[200][$propertyName] = null;
+                    }
+
+                } elseif ($updateResult===false) {
+                    // The node failed to update the properties for an
+                    // unknown reason
+                    foreach($remainingProperties as $propertyName=>$value) {
+                        $result[403][$propertyName] = null;
+                    }
+
+                } elseif (is_array($updateResult)) {
+
+                    // The node has detailed update information
+                    // We need to merge the results with the earlier results.
+                    foreach($updateResult as $status => $props) {
+                        if (is_array($props)) {
+                            if (!isset($result[$status]))
+                                $result[$status] = array();
+
+                            $result[$status] = array_merge($result[$status], $updateResult[$status]);
+                        }
+                    }
+
+                } else {
+                    throw new Exception('Invalid result from updateProperties');
+                }
+                $remainingProperties = array();
+            }
+
+        }
+
+        foreach($remainingProperties as $propertyName=>$value) {
+            // if there are remaining properties, it must mean
+            // there's a dependency failure
+            $result[424][$propertyName] = null;
+        }
+
+        // Removing empty array values
+        foreach($result as $status=>$props) {
+
+            if (count($props)===0) unset($result[$status]);
+
+        }
+        $result['href'] = $uri;
+        return $result;
+
+    }
+
+    /**
+     * This method checks the main HTTP preconditions.
+     *
+     * Currently these are:
+     *   * If-Match
+     *   * If-None-Match
+     *   * If-Modified-Since
+     *   * If-Unmodified-Since
+     *
+     * The method will return true if all preconditions are met
+     * The method will return false, or throw an exception if preconditions
+     * failed. If false is returned the operation should be aborted, and
+     * the appropriate HTTP response headers are already set.
+     *
+     * Normally this method will throw 412 Precondition Failed for failures
+     * related to If-None-Match, If-Match and If-Unmodified Since. It will
+     * set the status to 304 Not Modified for If-Modified_since.
+     *
+     * If the $handleAsGET argument is set to true, it will also return 304
+     * Not Modified for failure of the If-None-Match precondition. This is the
+     * desired behaviour for HTTP GET and HTTP HEAD requests.
+     *
+     * @param bool $handleAsGET
+     * @return bool
+     */
+    public function checkPreconditions($handleAsGET = false) {
+
+        $uri = $this->getRequestUri();
+        $node = null;
+        $lastMod = null;
+        $etag = null;
+
+        if ($ifMatch = $this->httpRequest->getHeader('If-Match')) {
+
+            // If-Match contains an entity tag. Only if the entity-tag
+            // matches we are allowed to make the request succeed.
+            // If the entity-tag is '*' we are only allowed to make the
+            // request succeed if a resource exists at that url.
+            try {
+                $node = $this->tree->getNodeForPath($uri);
+            } catch (Exception\NotFound $e) {
+                throw new Exception\PreconditionFailed('An If-Match header was specified and the resource did not exist','If-Match');
+            }
+
+            // Only need to check entity tags if they are not *
+            if ($ifMatch!=='*') {
+
+                // There can be multiple etags
+                $ifMatch = explode(',',$ifMatch);
+                $haveMatch = false;
+                foreach($ifMatch as $ifMatchItem) {
+
+                    // Stripping any extra spaces
+                    $ifMatchItem = trim($ifMatchItem,' ');
+
+                    $etag = $node->getETag();
+                    if ($etag===$ifMatchItem) {
+                        $haveMatch = true;
+                    } else {
+                        // Evolution has a bug where it sometimes prepends the "
+                        // with a \. This is our workaround.
+                        if (str_replace('\\"','"', $ifMatchItem) === $etag) {
+                            $haveMatch = true;
+                        }
+                    }
+
+                }
+                if (!$haveMatch) {
+                     throw new Exception\PreconditionFailed('An If-Match header was specified, but none of the specified the ETags matched.','If-Match');
+                }
+            }
+        }
+
+        if ($ifNoneMatch = $this->httpRequest->getHeader('If-None-Match')) {
+
+            // The If-None-Match header contains an etag.
+            // Only if the ETag does not match the current ETag, the request will succeed
+            // The header can also contain *, in which case the request
+            // will only succeed if the entity does not exist at all.
+            $nodeExists = true;
+            if (!$node) {
+                try {
+                    $node = $this->tree->getNodeForPath($uri);
+                } catch (Exception\NotFound $e) {
+                    $nodeExists = false;
+                }
+            }
+            if ($nodeExists) {
+                $haveMatch = false;
+                if ($ifNoneMatch==='*') $haveMatch = true;
+                else {
+
+                    // There might be multiple etags
+                    $ifNoneMatch = explode(',', $ifNoneMatch);
+                    $etag = $node->getETag();
+
+                    foreach($ifNoneMatch as $ifNoneMatchItem) {
+
+                        // Stripping any extra spaces
+                        $ifNoneMatchItem = trim($ifNoneMatchItem,' ');
+
+                        if ($etag===$ifNoneMatchItem) $haveMatch = true;
+
+                    }
+
+                }
+
+                if ($haveMatch) {
+                    if ($handleAsGET) {
+                        $this->httpResponse->sendStatus(304);
+                        return false;
+                    } else {
+                        throw new Exception\PreconditionFailed('An If-None-Match header was specified, but the ETag matched (or * was specified).','If-None-Match');
+                    }
+                }
+            }
+
+        }
+
+        if (!$ifNoneMatch && ($ifModifiedSince = $this->httpRequest->getHeader('If-Modified-Since'))) {
+
+            // The If-Modified-Since header contains a date. We
+            // will only return the entity if it has been changed since
+            // that date. If it hasn't been changed, we return a 304
+            // header
+            // Note that this header only has to be checked if there was no If-None-Match header
+            // as per the HTTP spec.
+            $date = HTTP\Util::parseHTTPDate($ifModifiedSince);
+
+            if ($date) {
+                if (is_null($node)) {
+                    $node = $this->tree->getNodeForPath($uri);
+                }
+                $lastMod = $node->getLastModified();
+                if ($lastMod) {
+                    $lastMod = new \DateTime('@' . $lastMod);
+                    if ($lastMod <= $date) {
+                        $this->httpResponse->sendStatus(304);
+                        $this->httpResponse->setHeader('Last-Modified', HTTP\Util::toHTTPDate($lastMod));
+                        return false;
+                    }
+                }
+            }
+        }
+
+        if ($ifUnmodifiedSince = $this->httpRequest->getHeader('If-Unmodified-Since')) {
+
+            // The If-Unmodified-Since will allow allow the request if the
+            // entity has not changed since the specified date.
+            $date = HTTP\Util::parseHTTPDate($ifUnmodifiedSince);
+
+            // We must only check the date if it's valid
+            if ($date) {
+                if (is_null($node)) {
+                    $node = $this->tree->getNodeForPath($uri);
+                }
+                $lastMod = $node->getLastModified();
+                if ($lastMod) {
+                    $lastMod = new \DateTime('@' . $lastMod);
+                    if ($lastMod > $date) {
+                        throw new Exception\PreconditionFailed('An If-Unmodified-Since header was specified, but the entity has been changed since the specified date.','If-Unmodified-Since');
+                    }
+                }
+            }
+
+        }
+        return true;
+
+    }
+
+    // }}}
+    // {{{ XML Readers & Writers
+
+
+    /**
+     * Generates a WebDAV propfind response body based on a list of nodes.
+     *
+     * If 'strip404s' is set to true, all 404 responses will be removed.
+     *
+     * @param array $fileProperties The list with nodes
+     * @param bool strip404s
+     * @return string
+     */
+    public function generateMultiStatus(array $fileProperties, $strip404s = false) {
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        //$dom->formatOutput = true;
+        $multiStatus = $dom->createElement('d:multistatus');
+        $dom->appendChild($multiStatus);
+
+        // Adding in default namespaces
+        foreach($this->xmlNamespaces as $namespace=>$prefix) {
+
+            $multiStatus->setAttribute('xmlns:' . $prefix,$namespace);
+
+        }
+
+        foreach($fileProperties as $entry) {
+
+            $href = $entry['href'];
+            unset($entry['href']);
+
+            if ($strip404s && isset($entry[404])) {
+                unset($entry[404]);
+            }
+
+            $response = new Property\Response($href,$entry);
+            $response->serialize($this,$multiStatus);
+
+        }
+
+        return $dom->saveXML();
+
+    }
+
+    /**
+     * This method parses a PropPatch request
+     *
+     * PropPatch changes the properties for a resource. This method
+     * returns a list of properties.
+     *
+     * The keys in the returned array contain the property name (e.g.: {DAV:}displayname,
+     * and the value contains the property value. If a property is to be removed the value
+     * will be null.
+     *
+     * @param string $body xml body
+     * @return array list of properties in need of updating or deletion
+     */
+    public function parsePropPatchRequest($body) {
+
+        //We'll need to change the DAV namespace declaration to something else in order to make it parsable
+        $dom = XMLUtil::loadDOMDocument($body);
+
+        $newProperties = array();
+
+        foreach($dom->firstChild->childNodes as $child) {
+
+            if ($child->nodeType !== XML_ELEMENT_NODE) continue;
+
+            $operation = XMLUtil::toClarkNotation($child);
+
+            if ($operation!=='{DAV:}set' && $operation!=='{DAV:}remove') continue;
+
+            $innerProperties = XMLUtil::parseProperties($child, $this->propertyMap);
+
+            foreach($innerProperties as $propertyName=>$propertyValue) {
+
+                if ($operation==='{DAV:}remove') {
+                    $propertyValue = null;
+                }
+
+                $newProperties[$propertyName] = $propertyValue;
+
+            }
+
+        }
+
+        return $newProperties;
+
+    }
+
+    /**
+     * This method parses the PROPFIND request and returns its information
+     *
+     * This will either be a list of properties, or an empty array; in which case
+     * an {DAV:}allprop was requested.
+     *
+     * @param string $body
+     * @return array
+     */
+    public function parsePropFindRequest($body) {
+
+        // If the propfind body was empty, it means IE is requesting 'all' properties
+        if (!$body) return array();
+
+        $dom = XMLUtil::loadDOMDocument($body);
+        $elem = $dom->getElementsByTagNameNS('urn:DAV','propfind')->item(0);
+        return array_keys(XMLUtil::parseProperties($elem));
+
+    }
+
+    // }}}
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/ServerPlugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ServerPlugin.php
new file mode 100644
index 0000000..a9061a3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/ServerPlugin.php
@@ -0,0 +1,90 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * The baseclass for all server plugins.
+ *
+ * Plugins can modify or extend the servers behaviour.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class ServerPlugin {
+
+    /**
+     * This initializes the plugin.
+     *
+     * This function is called by OldSabre\DAV\Server, after
+     * addPlugin is called.
+     *
+     * This method should set up the required event subscriptions.
+     *
+     * @param Server $server
+     * @return void
+     */
+    abstract public function initialize(Server $server);
+
+    /**
+     * This method should return a list of server-features.
+     *
+     * This is for example 'versioning' and is added to the DAV: header
+     * in an OPTIONS response.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array();
+
+    }
+
+    /**
+     * Use this method to tell the server this plugin defines additional
+     * HTTP methods.
+     *
+     * This method is passed a uri. It should only return HTTP methods that are
+     * available for the specified uri.
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getHTTPMethods($uri) {
+
+        return array();
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using \OldSabre\DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return get_class($this);
+
+    }
+
+    /**
+     * Returns a list of reports this plugin supports.
+     *
+     * This will be used in the {DAV:}supported-report-set property.
+     * Note that you still need to subscribe to the 'report' event to actually
+     * implement them
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getSupportedReportSet($uri) {
+
+        return array();
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleCollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleCollection.php
new file mode 100644
index 0000000..959096d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleCollection.php
@@ -0,0 +1,108 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * SimpleCollection
+ *
+ * The SimpleCollection is used to quickly setup static directory structures.
+ * Just create the object with a proper name, and add children to use it.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SimpleCollection extends Collection {
+
+    /**
+     * List of childnodes
+     *
+     * @var array
+     */
+    protected $children = array();
+
+    /**
+     * Name of this resource
+     *
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * Creates this node
+     *
+     * The name of the node must be passed, child nodes can also be passed.
+     * This nodes must be instances of INode
+     *
+     * @param string $name
+     * @param array $children
+     */
+    public function __construct($name,array $children = array()) {
+
+        $this->name = $name;
+        foreach($children as $child) {
+
+            if (!($child instanceof INode)) throw new Exception('Only instances of OldSabre\DAV\INode are allowed to be passed in the children argument');
+            $this->addChild($child);
+
+        }
+
+    }
+
+    /**
+     * Adds a new childnode to this collection
+     *
+     * @param INode $child
+     * @return void
+     */
+    public function addChild(INode $child) {
+
+        $this->children[$child->getName()] = $child;
+
+    }
+
+    /**
+     * Returns the name of the collection
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->name;
+
+    }
+
+    /**
+     * Returns a child object, by its name.
+     *
+     * This method makes use of the getChildren method to grab all the child nodes, and compares the name.
+     * Generally its wise to override this, as this can usually be optimized
+     *
+     * This method must throw OldSabre\DAV\Exception\NotFound if the node does not
+     * exist.
+     *
+     * @param string $name
+     * @throws Exception\NotFound
+     * @return INode
+     */
+    public function getChild($name) {
+
+        if (isset($this->children[$name])) return $this->children[$name];
+        throw new Exception\NotFound('File not found: ' . $name . ' in \'' . $this->getName() . '\'');
+
+    }
+
+    /**
+     * Returns a list of children for this collection
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        return array_values($this->children);
+
+    }
+
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleFile.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleFile.php
new file mode 100644
index 0000000..956d020
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/SimpleFile.php
@@ -0,0 +1,121 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * SimpleFile
+ *
+ * The 'SimpleFile' class is used to easily add read-only immutable files to
+ * the directory structure. One usecase would be to add a 'readme.txt' to a
+ * root of a webserver with some standard content.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SimpleFile extends File {
+
+    /**
+     * File contents
+     *
+     * @var string
+     */
+    protected $contents = array();
+
+    /**
+     * Name of this resource
+     *
+     * @var string
+     */
+    protected $name;
+
+    /**
+     * A mimetype, such as 'text/plain' or 'text/html'
+     *
+     * @var string
+     */
+    protected $mimeType;
+
+    /**
+     * Creates this node
+     *
+     * The name of the node must be passed, as well as the contents of the
+     * file.
+     *
+     * @param string $name
+     * @param string $contents
+     * @param string|null $mimeType
+     */
+    public function __construct($name, $contents, $mimeType = null) {
+
+        $this->name = $name;
+        $this->contents = $contents;
+        $this->mimeType = $mimeType;
+
+    }
+
+    /**
+     * Returns the node name for this file.
+     *
+     * This name is used to construct the url.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        return $this->name;
+
+    }
+
+    /**
+     * Returns the data
+     *
+     * This method may either return a string or a readable stream resource
+     *
+     * @return mixed
+     */
+    public function get() {
+
+        return $this->contents;
+
+    }
+
+    /**
+     * Returns the size of the file, in bytes.
+     *
+     * @return int
+     */
+    public function getSize() {
+
+        return strlen($this->contents);
+
+    }
+
+    /**
+     * Returns the ETag for a file
+     *
+     * An ETag is a unique identifier representing the current version of the file. If the file changes, the ETag MUST change.
+     * The ETag is an arbitrary string, but MUST be surrounded by double-quotes.
+     *
+     * Return null if the ETag can not effectively be determined
+     * @return string
+     */
+    public function getETag() {
+
+        return '"' . md5($this->contents) . '"';
+
+    }
+
+    /**
+     * Returns the mime-type for a file
+     *
+     * If null is returned, we'll assume application/octet-stream
+     * @return string
+     */
+    public function getContentType() {
+
+        return $this->mimeType;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/StringUtil.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/StringUtil.php
new file mode 100644
index 0000000..57e35c4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/StringUtil.php
@@ -0,0 +1,91 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * String utility
+ *
+ * This class is mainly used to implement the 'text-match' filter, used by both
+ * the CalDAV calendar-query REPORT, and CardDAV addressbook-query REPORT.
+ * Because they both need it, it was decided to put it in OldSabre\DAV instead.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class StringUtil {
+
+    /**
+     * Checks if a needle occurs in a haystack ;)
+     *
+     * @param string $haystack
+     * @param string $needle
+     * @param string $collation
+     * @param string $matchType
+     * @return bool
+     */
+    static public function textMatch($haystack, $needle, $collation, $matchType = 'contains') {
+
+        switch($collation) {
+
+            case 'i;ascii-casemap' :
+                // default strtolower takes locale into consideration
+                // we don't want this.
+                $haystack = str_replace(range('a','z'), range('A','Z'), $haystack);
+                $needle = str_replace(range('a','z'), range('A','Z'), $needle);
+                break;
+
+            case 'i;octet' :
+                // Do nothing
+                break;
+
+            case 'i;unicode-casemap' :
+                $haystack = mb_strtoupper($haystack, 'UTF-8');
+                $needle = mb_strtoupper($needle, 'UTF-8');
+                break;
+
+            default :
+                throw new Exception\BadRequest('Collation type: ' . $collation . ' is not supported');
+
+        }
+
+        switch($matchType) {
+
+            case 'contains' :
+                return strpos($haystack, $needle)!==false;
+            case 'equals' :
+                return $haystack === $needle;
+            case 'starts-with' :
+                return strpos($haystack, $needle)===0;
+            case 'ends-with' :
+                return strrpos($haystack, $needle)===strlen($haystack)-strlen($needle);
+            default :
+                throw new Exception\BadRequest('Match-type: ' . $matchType . ' is not supported');
+
+        }
+
+    }
+
+    /**
+     * This method takes an input string, checks if it's not valid UTF-8 and
+     * attempts to convert it to UTF-8 if it's not.
+     *
+     * Note that currently this can only convert ISO-8559-1 to UTF-8 (latin-1),
+     * anything else will likely fail.
+     *
+     * @param string $input
+     * @return string
+     */
+    static public function ensureUTF8($input) {
+
+        $encoding = mb_detect_encoding($input , array('UTF-8','ISO-8859-1'), true);
+
+        if ($encoding === 'ISO-8859-1') {
+            return utf8_encode($input);
+        } else {
+            return $input;
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/TemporaryFileFilterPlugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/TemporaryFileFilterPlugin.php
new file mode 100644
index 0000000..5a2a2f0
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/TemporaryFileFilterPlugin.php
@@ -0,0 +1,289 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * Temporary File Filter Plugin
+ *
+ * The purpose of this filter is to intercept some of the garbage files
+ * operation systems and applications tend to generate when mounting
+ * a WebDAV share as a disk.
+ *
+ * It will intercept these files and place them in a separate directory.
+ * these files are not deleted automatically, so it is adviceable to
+ * delete these after they are not accessed for 24 hours.
+ *
+ * Currently it supports:
+ *   * OS/X style resource forks and .DS_Store
+ *   * desktop.ini and Thumbs.db (windows)
+ *   * .*.swp (vim temporary files)
+ *   * .dat.* (smultron temporary files)
+ *
+ * Additional patterns can be added, by adding on to the
+ * temporaryFilePatterns property.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class TemporaryFileFilterPlugin extends ServerPlugin {
+
+    /**
+     * This is the list of patterns we intercept.
+     * If new patterns are added, they must be valid patterns for preg_match.
+     *
+     * @var array
+     */
+    public $temporaryFilePatterns = array(
+        '/^\._(.*)$/',     // OS/X resource forks
+        '/^.DS_Store$/',   // OS/X custom folder settings
+        '/^desktop.ini$/', // Windows custom folder settings
+        '/^Thumbs.db$/',   // Windows thumbnail cache
+        '/^.(.*).swp$/',   // ViM temporary files
+        '/^\.dat(.*)$/',   // Smultron seems to create these
+        '/^~lock.(.*)#$/', // Windows 7 lockfiles
+    );
+
+    /**
+     * A reference to the main Server class
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * This is the directory where this plugin
+     * will store it's files.
+     *
+     * @var string
+     */
+    private $dataDir;
+
+    /**
+     * Creates the plugin.
+     *
+     * Make sure you specify a directory for your files. If you don't, we
+     * will use PHP's directory for session-storage instead, and you might
+     * not want that.
+     *
+     * @param string|null $dataDir
+     */
+    public function __construct($dataDir = null) {
+
+        if (!$dataDir) $dataDir = ini_get('session.save_path').'/sabredav/';
+        if (!is_dir($dataDir)) mkdir($dataDir);
+        $this->dataDir = $dataDir;
+
+    }
+
+    /**
+     * Initialize the plugin
+     *
+     * This is called automatically be the Server class after this plugin is
+     * added with OldSabre\DAV\Server::addPlugin()
+     *
+     * @param Server $server
+     * @return void
+     */
+    public function initialize(Server $server) {
+
+        $this->server = $server;
+        $server->subscribeEvent('beforeMethod',array($this,'beforeMethod'));
+        $server->subscribeEvent('beforeCreateFile',array($this,'beforeCreateFile'));
+
+    }
+
+    /**
+     * This method is called before any HTTP method handler
+     *
+     * This method intercepts any GET, DELETE, PUT and PROPFIND calls to
+     * filenames that are known to match the 'temporary file' regex.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function beforeMethod($method, $uri) {
+
+        if (!$tempLocation = $this->isTempFile($uri))
+            return true;
+
+        switch($method) {
+            case 'GET' :
+                return $this->httpGet($tempLocation);
+            case 'PUT' :
+                return $this->httpPut($tempLocation);
+            case 'PROPFIND' :
+                return $this->httpPropfind($tempLocation, $uri);
+            case 'DELETE' :
+                return $this->httpDelete($tempLocation);
+         }
+         return true;
+
+    }
+
+    /**
+     * This method is invoked if some subsystem creates a new file.
+     *
+     * This is used to deal with HTTP LOCK requests which create a new
+     * file.
+     *
+     * @param string $uri
+     * @param resource $data
+     * @return bool
+     */
+    public function beforeCreateFile($uri,$data) {
+
+        if ($tempPath = $this->isTempFile($uri)) {
+
+            $hR = $this->server->httpResponse;
+            $hR->setHeader('X-Sabre-Temp','true');
+            file_put_contents($tempPath,$data);
+            return false;
+        }
+        return true;
+
+    }
+
+    /**
+     * This method will check if the url matches the temporary file pattern
+     * if it does, it will return an path based on $this->dataDir for the
+     * temporary file storage.
+     *
+     * @param string $path
+     * @return boolean|string
+     */
+    protected function isTempFile($path) {
+
+        // We're only interested in the basename.
+        list(, $tempPath) = URLUtil::splitPath($path);
+
+        foreach($this->temporaryFilePatterns as $tempFile) {
+
+            if (preg_match($tempFile,$tempPath)) {
+                return $this->getDataDir() . '/sabredav_' . md5($path) . '.tempfile';
+            }
+
+        }
+
+        return false;
+
+    }
+
+
+    /**
+     * This method handles the GET method for temporary files.
+     * If the file doesn't exist, it will return false which will kick in
+     * the regular system for the GET method.
+     *
+     * @param string $tempLocation
+     * @return bool
+     */
+    public function httpGet($tempLocation) {
+
+        if (!file_exists($tempLocation)) return true;
+
+        $hR = $this->server->httpResponse;
+        $hR->setHeader('Content-Type','application/octet-stream');
+        $hR->setHeader('Content-Length',filesize($tempLocation));
+        $hR->setHeader('X-Sabre-Temp','true');
+        $hR->sendStatus(200);
+        $hR->sendBody(fopen($tempLocation,'r'));
+        return false;
+
+    }
+
+    /**
+     * This method handles the PUT method.
+     *
+     * @param string $tempLocation
+     * @return bool
+     */
+    public function httpPut($tempLocation) {
+
+        $hR = $this->server->httpResponse;
+        $hR->setHeader('X-Sabre-Temp','true');
+
+        $newFile = !file_exists($tempLocation);
+
+        if (!$newFile && ($this->server->httpRequest->getHeader('If-None-Match'))) {
+             throw new Exception\PreconditionFailed('The resource already exists, and an If-None-Match header was supplied');
+        }
+
+        file_put_contents($tempLocation,$this->server->httpRequest->getBody());
+        $hR->sendStatus($newFile?201:200);
+        return false;
+
+    }
+
+    /**
+     * This method handles the DELETE method.
+     *
+     * If the file didn't exist, it will return false, which will make the
+     * standard HTTP DELETE handler kick in.
+     *
+     * @param string $tempLocation
+     * @return bool
+     */
+    public function httpDelete($tempLocation) {
+
+        if (!file_exists($tempLocation)) return true;
+
+        unlink($tempLocation);
+        $hR = $this->server->httpResponse;
+        $hR->setHeader('X-Sabre-Temp','true');
+        $hR->sendStatus(204);
+        return false;
+
+    }
+
+    /**
+     * This method handles the PROPFIND method.
+     *
+     * It's a very lazy method, it won't bother checking the request body
+     * for which properties were requested, and just sends back a default
+     * set of properties.
+     *
+     * @param string $tempLocation
+     * @param string $uri
+     * @return bool
+     */
+    public function httpPropfind($tempLocation, $uri) {
+
+        if (!file_exists($tempLocation)) return true;
+
+        $hR = $this->server->httpResponse;
+        $hR->setHeader('X-Sabre-Temp','true');
+        $hR->sendStatus(207);
+        $hR->setHeader('Content-Type','application/xml; charset=utf-8');
+
+        $this->server->parsePropFindRequest($this->server->httpRequest->getBody(true));
+
+        $properties = array(
+            'href' => $uri,
+            200 => array(
+                '{DAV:}getlastmodified' => new Property\GetLastModified(filemtime($tempLocation)),
+                '{DAV:}getcontentlength' => filesize($tempLocation),
+                '{DAV:}resourcetype' => new Property\ResourceType(null),
+                '{'.Server::NS_SABREDAV.'}tempFile' => true,
+
+            ),
+         );
+
+        $data = $this->server->generateMultiStatus(array($properties));
+        $hR->sendBody($data);
+        return false;
+
+    }
+
+
+    /**
+     * This method returns the directory where the temporary files should be stored.
+     *
+     * @return string
+     */
+    protected function getDataDir()
+    {
+        return $this->dataDir;
+    }
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree.php
new file mode 100644
index 0000000..8313918
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree.php
@@ -0,0 +1,193 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * Abstract tree object
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class Tree {
+
+    /**
+     * This function must return an INode object for a path
+     * If a Path doesn't exist, thrown a Exception_NotFound
+     *
+     * @param string $path
+     * @throws Exception\NotFound
+     * @return INode
+     */
+    abstract function getNodeForPath($path);
+
+    /**
+     * This function allows you to check if a node exists.
+     *
+     * Implementors of this class should override this method to make
+     * it cheaper.
+     *
+     * @param string $path
+     * @return bool
+     */
+    public function nodeExists($path) {
+
+        try {
+
+            $this->getNodeForPath($path);
+            return true;
+
+        } catch (Exception\NotFound $e) {
+
+            return false;
+
+        }
+
+    }
+
+    /**
+     * Copies a file from path to another
+     *
+     * @param string $sourcePath The source location
+     * @param string $destinationPath The full destination path
+     * @return void
+     */
+    public function copy($sourcePath, $destinationPath) {
+
+        $sourceNode = $this->getNodeForPath($sourcePath);
+
+        // grab the dirname and basename components
+        list($destinationDir, $destinationName) = URLUtil::splitPath($destinationPath);
+
+        $destinationParent = $this->getNodeForPath($destinationDir);
+        $this->copyNode($sourceNode,$destinationParent,$destinationName);
+
+        $this->markDirty($destinationDir);
+
+    }
+
+    /**
+     * Moves a file from one location to another
+     *
+     * @param string $sourcePath The path to the file which should be moved
+     * @param string $destinationPath The full destination path, so not just the destination parent node
+     * @return int
+     */
+    public function move($sourcePath, $destinationPath) {
+
+        list($sourceDir, $sourceName) = URLUtil::splitPath($sourcePath);
+        list($destinationDir, $destinationName) = URLUtil::splitPath($destinationPath);
+
+        if ($sourceDir===$destinationDir) {
+            $renameable = $this->getNodeForPath($sourcePath);
+            $renameable->setName($destinationName);
+        } else {
+            $this->copy($sourcePath,$destinationPath);
+            $this->getNodeForPath($sourcePath)->delete();
+        }
+        $this->markDirty($sourceDir);
+        $this->markDirty($destinationDir);
+
+    }
+
+    /**
+     * Deletes a node from the tree
+     *
+     * @param string $path
+     * @return void
+     */
+    public function delete($path) {
+
+        $node = $this->getNodeForPath($path);
+        $node->delete();
+
+        list($parent) = URLUtil::splitPath($path);
+        $this->markDirty($parent);
+
+    }
+
+    /**
+     * Returns a list of childnodes for a given path.
+     *
+     * @param string $path
+     * @return array
+     */
+    public function getChildren($path) {
+
+        $node = $this->getNodeForPath($path);
+        return $node->getChildren();
+
+    }
+
+    /**
+     * This method is called with every tree update
+     *
+     * Examples of tree updates are:
+     *   * node deletions
+     *   * node creations
+     *   * copy
+     *   * move
+     *   * renaming nodes
+     *
+     * If Tree classes implement a form of caching, this will allow
+     * them to make sure caches will be expired.
+     *
+     * If a path is passed, it is assumed that the entire subtree is dirty
+     *
+     * @param string $path
+     * @return void
+     */
+    public function markDirty($path) {
+
+
+    }
+
+    /**
+     * copyNode
+     *
+     * @param INode $source
+     * @param ICollection $destinationParent
+     * @param string $destinationName
+     * @return void
+     */
+    protected function copyNode(INode $source,ICollection $destinationParent,$destinationName = null) {
+
+        if (!$destinationName) $destinationName = $source->getName();
+
+        if ($source instanceof IFile) {
+
+            $data = $source->get();
+
+            // If the body was a string, we need to convert it to a stream
+            if (is_string($data)) {
+                $stream = fopen('php://temp','r+');
+                fwrite($stream,$data);
+                rewind($stream);
+                $data = $stream;
+            }
+            $destinationParent->createFile($destinationName,$data);
+            $destination = $destinationParent->getChild($destinationName);
+
+        } elseif ($source instanceof ICollection) {
+
+            $destinationParent->createDirectory($destinationName);
+
+            $destination = $destinationParent->getChild($destinationName);
+            foreach($source->getChildren() as $child) {
+
+                $this->copyNode($child,$destination);
+
+            }
+
+        }
+        if ($source instanceof IProperties && $destination instanceof IProperties) {
+
+            $props = $source->getProperties(array());
+            $destination->updateProperties($props);
+
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree/Filesystem.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree/Filesystem.php
new file mode 100644
index 0000000..9d1a638
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Tree/Filesystem.php
@@ -0,0 +1,133 @@
+<?php
+
+namespace OldSabre\DAV\Tree;
+
+use OldSabre\DAV;
+
+/**
+ * FileSystem Tree
+ *
+ * This class is an alternative to the standard ObjectTree. This tree can only
+ * use OldSabre\DAV\FS\Directory and File classes, but as a result it allows for a few
+ * optimizations that otherwise wouldn't be possible.
+ *
+ * Specifically copying and moving are much, much faster.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Filesystem extends DAV\Tree {
+
+    /**
+     * Base url on the filesystem.
+     *
+     * @var string
+     */
+    protected $basePath;
+
+    /**
+     * Creates this tree
+     *
+     * Supply the path you'd like to share.
+     *
+     * @param string $basePath
+     */
+    public function __construct($basePath) {
+
+        $this->basePath = $basePath;
+
+    }
+
+    /**
+     * Returns a new node for the given path
+     *
+     * @param string $path
+     * @return DAV\FS\Node
+     */
+    public function getNodeForPath($path) {
+
+        $realPath = $this->getRealPath($path);
+        if (!file_exists($realPath)) { 
+            throw new DAV\Exception\NotFound('File at location ' . $realPath . ' not found');
+        }
+        if (is_dir($realPath)) {
+            return new DAV\FS\Directory($realPath);
+        } else {
+            return new DAV\FS\File($realPath);
+        }
+
+    }
+
+    /**
+     * Returns the real filesystem path for a webdav url.
+     *
+     * @param string $publicPath
+     * @return string
+     */
+    protected function getRealPath($publicPath) {
+
+        return rtrim($this->basePath,'/') . '/' . trim($publicPath,'/');
+
+    }
+
+    /**
+     * Copies a file or directory.
+     *
+     * This method must work recursively and delete the destination
+     * if it exists
+     *
+     * @param string $source
+     * @param string $destination
+     * @return void
+     */
+    public function copy($source,$destination) {
+
+        $source = $this->getRealPath($source);
+        $destination = $this->getRealPath($destination);
+        $this->realCopy($source,$destination);
+
+    }
+
+    /**
+     * Used by self::copy
+     *
+     * @param string $source
+     * @param string $destination
+     * @return void
+     */
+    protected function realCopy($source,$destination) {
+
+        if (is_file($source)) {
+            copy($source,$destination);
+        } else {
+            mkdir($destination);
+            foreach(scandir($source) as $subnode) {
+
+                if ($subnode=='.' || $subnode=='..') continue;
+                $this->realCopy($source.'/'.$subnode,$destination.'/'.$subnode);
+
+            }
+        }
+
+    }
+
+    /**
+     * Moves a file or directory recursively.
+     *
+     * If the destination exists, delete it first.
+     *
+     * @param string $source
+     * @param string $destination
+     * @return void
+     */
+    public function move($source,$destination) {
+
+        $source = $this->getRealPath($source);
+        $destination = $this->getRealPath($destination);
+        rename($source,$destination);
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/URLUtil.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/URLUtil.php
new file mode 100644
index 0000000..f6ebb47
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/URLUtil.php
@@ -0,0 +1,124 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * URL utility class
+ *
+ * This class provides methods to deal with encoding and decoding url (percent encoded) strings.
+ *
+ * It was not possible to use PHP's built-in methods for this, because some clients don't like
+ * encoding of certain characters.
+ *
+ * Specifically, it was found that GVFS (gnome's webdav client) does not like encoding of ( and
+ * ). Since these are reserved, but don't have a reserved meaning in url, these characters are
+ * kept as-is.
+ *
+ * It was also discovered that versions of the SOGO connector for thunderbird
+ * has issues with urlencoded colons.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class URLUtil {
+
+    /**
+     * Encodes the path of a url.
+     *
+     * slashes (/) are treated as path-separators.
+     *
+     * @param string $path
+     * @return string
+     */
+    static function encodePath($path) {
+
+        return preg_replace_callback('/([^A-Za-z0-9_\-\.~\(\)\/:])/',function($match) {
+
+            return '%'.sprintf('%02x',ord($match[0]));
+
+        }, $path);
+
+    }
+
+    /**
+     * Encodes a 1 segment of a path
+     *
+     * Slashes are considered part of the name, and are encoded as %2f
+     *
+     * @param string $pathSegment
+     * @return string
+     */
+    static function encodePathSegment($pathSegment) {
+
+        return preg_replace_callback('/([^A-Za-z0-9_\-\.~\(\):])/',function($match) {
+
+            return '%'.sprintf('%02x',ord($match[0]));
+
+        }, $pathSegment);
+    }
+
+    /**
+     * Decodes a url-encoded path
+     *
+     * @param string $path
+     * @return string
+     */
+    static function decodePath($path) {
+
+        return self::decodePathSegment($path);
+
+    }
+
+    /**
+     * Decodes a url-encoded path segment
+     *
+     * @param string $path
+     * @return string
+     */
+    static function decodePathSegment($path) {
+
+        $path = rawurldecode($path);
+        $encoding = mb_detect_encoding($path, array('UTF-8','ISO-8859-1'));
+
+        switch($encoding) {
+
+            case 'ISO-8859-1' :
+                $path = utf8_encode($path);
+
+        }
+
+        return $path;
+
+    }
+
+    /**
+     * Returns the 'dirname' and 'basename' for a path.
+     *
+     * The reason there is a custom function for this purpose, is because
+     * basename() is locale aware (behaviour changes if C locale or a UTF-8 locale is used)
+     * and we need a method that just operates on UTF-8 characters.
+     *
+     * In addition basename and dirname are platform aware, and will treat backslash (\) as a
+     * directory separator on windows.
+     *
+     * This method returns the 2 components as an array.
+     *
+     * If there is no dirname, it will return an empty string. Any / appearing at the end of the
+     * string is stripped off.
+     *
+     * @param string $path
+     * @return array
+     */
+    static function splitPath($path) {
+
+        $matches = array();
+        if(preg_match('/^(?:(?:(.*)(?:\/+))?([^\/]+))(?:\/?)$/u',$path,$matches)) {
+            return array($matches[1],$matches[2]);
+        } else {
+            return array(null,null);
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/UUIDUtil.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/UUIDUtil.php
new file mode 100644
index 0000000..aed84e8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/UUIDUtil.php
@@ -0,0 +1,64 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * UUID Utility
+ *
+ * This class has static methods to generate and validate UUID's.
+ * UUIDs are used a decent amount within various *DAV standards, so it made
+ * sense to include it.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class UUIDUtil {
+
+    /**
+     * Returns a pseudo-random v4 UUID
+     *
+     * This function is based on a comment by Andrew Moore on php.net
+     *
+     * @see http://www.php.net/manual/en/function.uniqid.php#94959
+     * @return string
+     */
+    static function getUUID() {
+
+        return sprintf( '%04x%04x-%04x-%04x-%04x-%04x%04x%04x',
+            // 32 bits for "time_low"
+            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ),
+
+            // 16 bits for "time_mid"
+            mt_rand( 0, 0xffff ),
+
+            // 16 bits for "time_hi_and_version",
+            // four most significant bits holds version number 4
+            mt_rand( 0, 0x0fff ) | 0x4000,
+
+            // 16 bits, 8 bits for "clk_seq_hi_res",
+            // 8 bits for "clk_seq_low",
+            // two most significant bits holds zero and one for variant DCE1.1
+            mt_rand( 0, 0x3fff ) | 0x8000,
+
+            // 48 bits for "node"
+            mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff ), mt_rand( 0, 0xffff )
+        );
+    }
+
+    /**
+     * Checks if a string is a valid UUID.
+     *
+     * @param string $uuid
+     * @return bool
+     */
+    static function validateUUID($uuid) {
+
+        return preg_match(
+            '/^[a-f0-9]{8}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{4}-[a-f0-9]{12}$/i',
+            $uuid
+        ) == true;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/Version.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Version.php
new file mode 100644
index 0000000..62e35b3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/Version.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * This class contains the SabreDAV version constants.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '1.8.12';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAV/XMLUtil.php b/calendar/lib/SabreDAV/lib/OldSabre/DAV/XMLUtil.php
new file mode 100644
index 0000000..5ee0b5d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAV/XMLUtil.php
@@ -0,0 +1,191 @@
+<?php
+
+namespace OldSabre\DAV;
+
+/**
+ * XML utilities for WebDAV
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class XMLUtil {
+
+    /**
+     * Returns the 'clark notation' for an element.
+     *
+     * For example, and element encoded as:
+     * <b:myelem xmlns:b="http://www.example.org/" />
+     * will be returned as:
+     * {http://www.example.org}myelem
+     *
+     * This format is used throughout the SabreDAV sourcecode.
+     * Elements encoded with the urn:DAV namespace will
+     * be returned as if they were in the DAV: namespace. This is to avoid
+     * compatibility problems.
+     *
+     * This function will return null if a nodetype other than an Element is passed.
+     *
+     * @param \DOMNode $dom
+     * @return string
+     */
+    static function toClarkNotation(\DOMNode $dom) {
+
+        if ($dom->nodeType !== XML_ELEMENT_NODE) return null;
+
+        // Mapping back to the real namespace, in case it was dav
+        if ($dom->namespaceURI=='urn:DAV') $ns = 'DAV:'; else $ns = $dom->namespaceURI;
+
+        // Mapping to clark notation
+        return '{' . $ns . '}' . $dom->localName;
+
+    }
+
+    /**
+     * Parses a clark-notation string, and returns the namespace and element
+     * name components.
+     *
+     * If the string was invalid, it will throw an InvalidArgumentException.
+     *
+     * @param string $str
+     * @throws InvalidArgumentException
+     * @return array
+     */
+    static function parseClarkNotation($str) {
+
+        if (!preg_match('/^{([^}]*)}(.*)$/',$str,$matches)) {
+            throw new \InvalidArgumentException('\'' . $str . '\' is not a valid clark-notation formatted string');
+        }
+
+        return array(
+            $matches[1],
+            $matches[2]
+        );
+
+    }
+
+    /**
+     * This method takes an XML document (as string) and converts all instances of the
+     * DAV: namespace to urn:DAV
+     *
+     * This is unfortunately needed, because the DAV: namespace violates the xml namespaces
+     * spec, and causes the DOM to throw errors
+     *
+     * @param string $xmlDocument
+     * @return array|string|null
+     */
+    static function convertDAVNamespace($xmlDocument) {
+
+        // This is used to map the DAV: namespace to urn:DAV. This is needed, because the DAV:
+        // namespace is actually a violation of the XML namespaces specification, and will cause errors
+        return preg_replace("/xmlns(:[A-Za-z0-9_]*)?=(\"|\')DAV:(\\2)/","xmlns\\1=\\2urn:DAV\\2",$xmlDocument);
+
+    }
+
+    /**
+     * This method provides a generic way to load a DOMDocument for WebDAV use.
+     *
+     * This method throws a OldSabre\DAV\Exception\BadRequest exception for any xml errors.
+     * It does not preserve whitespace, and it converts the DAV: namespace to urn:DAV.
+     *
+     * @param string $xml
+     * @throws OldSabre\DAV\Exception\BadRequest
+     * @return DOMDocument
+     */
+    static function loadDOMDocument($xml) {
+
+        if (empty($xml))
+            throw new Exception\BadRequest('Empty XML document sent');
+
+        // The BitKinex client sends xml documents as UTF-16. PHP 5.3.1 (and presumably lower)
+        // does not support this, so we must intercept this and convert to UTF-8.
+        if (substr($xml,0,12) === "\x3c\x00\x3f\x00\x78\x00\x6d\x00\x6c\x00\x20\x00") {
+
+            // Note: the preceeding byte sequence is "<?xml" encoded as UTF_16, without the BOM.
+            $xml = iconv('UTF-16LE','UTF-8',$xml);
+
+            // Because the xml header might specify the encoding, we must also change this.
+            // This regex looks for the string encoding="UTF-16" and replaces it with
+            // encoding="UTF-8".
+            $xml = preg_replace('|<\?xml([^>]*)encoding="UTF-16"([^>]*)>|u','<?xml\1encoding="UTF-8"\2>',$xml);
+
+        }
+
+        // Retaining old error setting
+        $oldErrorSetting =  libxml_use_internal_errors(true);
+        // Fixes an XXE vulnerability on PHP versions older than 5.3.23 or
+        // 5.4.13.
+        $oldEntityLoaderSetting = libxml_disable_entity_loader(true);
+
+        // Clearing any previous errors
+        libxml_clear_errors();
+
+        $dom = new \DOMDocument();
+
+        // We don't generally care about any whitespace
+        $dom->preserveWhiteSpace = false;
+
+        $dom->loadXML(self::convertDAVNamespace($xml),LIBXML_NOWARNING | LIBXML_NOERROR);
+
+        if ($error = libxml_get_last_error()) {
+            libxml_clear_errors();
+            throw new Exception\BadRequest('The request body had an invalid XML body. (message: ' . $error->message . ', errorcode: ' . $error->code . ', line: ' . $error->line . ')');
+        }
+
+        // Restoring old mechanism for error handling
+        if ($oldErrorSetting===false) libxml_use_internal_errors(false);
+        if ($oldEntityLoaderSetting===false) libxml_disable_entity_loader(false);
+
+        return $dom;
+
+    }
+
+    /**
+     * Parses all WebDAV properties out of a DOM Element
+     *
+     * Generally WebDAV properties are enclosed in {DAV:}prop elements. This
+     * method helps by going through all these and pulling out the actual
+     * propertynames, making them array keys and making the property values,
+     * well.. the array values.
+     *
+     * If no value was given (self-closing element) null will be used as the
+     * value. This is used in for example PROPFIND requests.
+     *
+     * Complex values are supported through the propertyMap argument. The
+     * propertyMap should have the clark-notation properties as it's keys, and
+     * classnames as values.
+     *
+     * When any of these properties are found, the unserialize() method will be
+     * (statically) called. The result of this method is used as the value.
+     *
+     * @param \DOMElement $parentNode
+     * @param array $propertyMap
+     * @return array
+     */
+    static function parseProperties(\DOMElement $parentNode, array $propertyMap = array()) {
+
+        $propList = array();
+        foreach($parentNode->childNodes as $propNode) {
+
+            if (self::toClarkNotation($propNode)!=='{DAV:}prop') continue;
+
+            foreach($propNode->childNodes as $propNodeData) {
+
+                /* If there are no elements in here, we actually get 1 text node, this special case is dedicated to netdrive */
+                if ($propNodeData->nodeType != XML_ELEMENT_NODE) continue;
+
+                $propertyName = self::toClarkNotation($propNodeData);
+                if (isset($propertyMap[$propertyName])) {
+                    $propList[$propertyName] = call_user_func(array($propertyMap[$propertyName],'unserialize'),$propNodeData);
+                } else {
+                    $propList[$propertyName] = $propNodeData->textContent;
+                }
+            }
+
+
+        }
+        return $propList;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/AbstractPrincipalCollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/AbstractPrincipalCollection.php
new file mode 100644
index 0000000..1367037
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/AbstractPrincipalCollection.php
@@ -0,0 +1,155 @@
+<?php
+
+namespace OldSabre\DAVACL;
+use OldSabre\DAV;
+
+/**
+ * Principals Collection
+ *
+ * This is a helper class that easily allows you to create a collection that
+ * has a childnode for every principal.
+ *
+ * To use this class, simply implement the getChildForPrincipal method.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractPrincipalCollection extends DAV\Collection implements IPrincipalCollection {
+
+    /**
+     * Node or 'directory' name.
+     *
+     * @var string
+     */
+    protected $path;
+
+    /**
+     * Principal backend
+     *
+     * @var PrincipalBackend\BackendInterface
+     */
+    protected $principalBackend;
+
+    /**
+     * If this value is set to true, it effectively disables listing of users
+     * it still allows user to find other users if they have an exact url.
+     *
+     * @var bool
+     */
+    public $disableListing = false;
+
+    /**
+     * Creates the object
+     *
+     * This object must be passed the principal backend. This object will
+     * filter all principals from a specified prefix ($principalPrefix). The
+     * default is 'principals', if your principals are stored in a different
+     * collection, override $principalPrefix
+     *
+     *
+     * @param PrincipalBackend\BackendInterface $principalBackend
+     * @param string $principalPrefix
+     */
+    public function __construct(PrincipalBackend\BackendInterface $principalBackend, $principalPrefix = 'principals') {
+
+        $this->principalPrefix = $principalPrefix;
+        $this->principalBackend = $principalBackend;
+
+    }
+
+    /**
+     * This method returns a node for a principal.
+     *
+     * The passed array contains principal information, and is guaranteed to
+     * at least contain a uri item. Other properties may or may not be
+     * supplied by the authentication backend.
+     *
+     * @param array $principalInfo
+     * @return IPrincipal
+     */
+    abstract function getChildForPrincipal(array $principalInfo);
+
+    /**
+     * Returns the name of this collection.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        list(,$name) = DAV\URLUtil::splitPath($this->principalPrefix);
+        return $name;
+
+    }
+
+    /**
+     * Return the list of users
+     *
+     * @return array
+     */
+    public function getChildren() {
+
+        if ($this->disableListing)
+            throw new DAV\Exception\MethodNotAllowed('Listing members of this collection is disabled');
+
+        $children = array();
+        foreach($this->principalBackend->getPrincipalsByPrefix($this->principalPrefix) as $principalInfo) {
+
+            $children[] = $this->getChildForPrincipal($principalInfo);
+
+
+        }
+        return $children;
+
+    }
+
+    /**
+     * Returns a child object, by its name.
+     *
+     * @param string $name
+     * @throws DAV\Exception\NotFound
+     * @return IPrincipal
+     */
+    public function getChild($name) {
+
+        $principalInfo = $this->principalBackend->getPrincipalByPath($this->principalPrefix . '/' . $name);
+        if (!$principalInfo) throw new DAV\Exception\NotFound('Principal with name ' . $name . ' not found');
+        return $this->getChildForPrincipal($principalInfo);
+
+    }
+
+    /**
+     * This method is used to search for principals matching a set of
+     * properties.
+     *
+     * This search is specifically used by RFC3744's principal-property-search
+     * REPORT. You should at least allow searching on
+     * http://sabredav.org/ns}email-address.
+     *
+     * The actual search should be a unicode-non-case-sensitive search. The
+     * keys in searchProperties are the WebDAV property names, while the values
+     * are the property values to search on.
+     *
+     * If multiple properties are being searched on, the search should be
+     * AND'ed.
+     *
+     * This method should simply return a list of 'child names', which may be
+     * used to call $this->getChild in the future.
+     *
+     * @param array $searchProperties
+     * @return array
+     */
+    public function searchPrincipals(array $searchProperties) {
+
+        $result = $this->principalBackend->searchPrincipals($this->principalPrefix, $searchProperties);
+        $r = array();
+
+        foreach($result as $row) {
+            list(, $r[]) = DAV\URLUtil::splitPath($row);
+        }
+
+        return $r;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/AceConflict.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/AceConflict.php
new file mode 100644
index 0000000..a636bdc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/AceConflict.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace OldSabre\DAVACL\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * This exception is thrown when a client attempts to set conflicting
+ * permissions.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AceConflict extends DAV\Exception\Conflict {
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {DAV:}no-ace-conflict element as defined in rfc3744
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS('DAV:','d:no-ace-conflict');
+        $errorNode->appendChild($np);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NeedPrivileges.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NeedPrivileges.php
new file mode 100644
index 0000000..c2c3ab1
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NeedPrivileges.php
@@ -0,0 +1,83 @@
+<?php
+
+namespace OldSabre\DAVACL\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * NeedPrivileges
+ *
+ * The 403-need privileges is thrown when a user didn't have the appropriate
+ * permissions to perform an operation
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NeedPrivileges extends DAV\Exception\Forbidden {
+
+    /**
+     * The relevant uri
+     *
+     * @var string
+     */
+    protected $uri;
+
+    /**
+     * The privileges the user didn't have.
+     *
+     * @var array
+     */
+    protected $privileges;
+
+    /**
+     * Constructor
+     *
+     * @param string $uri
+     * @param array $privileges
+     */
+    public function __construct($uri,array $privileges) {
+
+        $this->uri = $uri;
+        $this->privileges = $privileges;
+
+        parent::__construct('User did not have the required privileges (' . implode(',', $privileges) . ') for path "' . $uri . '"');
+
+    }
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {DAV:}need-privileges element as defined in rfc3744
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS('DAV:','d:need-privileges');
+        $errorNode->appendChild($np);
+
+        foreach($this->privileges as $privilege) {
+
+            $resource = $doc->createElementNS('DAV:','d:resource');
+            $np->appendChild($resource);
+
+            $resource->appendChild($doc->createElementNS('DAV:','d:href',$server->getBaseUri() . $this->uri));
+
+            $priv = $doc->createElementNS('DAV:','d:privilege');
+            $resource->appendChild($priv);
+
+            preg_match('/^{([^}]*)}(.*)$/',$privilege,$privilegeParts);
+            $priv->appendChild($doc->createElementNS($privilegeParts[1],'d:' . $privilegeParts[2]));
+
+
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NoAbstract.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NoAbstract.php
new file mode 100644
index 0000000..b7c78d9
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NoAbstract.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace OldSabre\DAVACL\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * This exception is thrown when a user tries to set a privilege that's marked
+ * as abstract.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NoAbstract extends DAV\Exception\PreconditionFailed {
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {DAV:}no-abstract element as defined in rfc3744
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS('DAV:','d:no-abstract');
+        $errorNode->appendChild($np);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotRecognizedPrincipal.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotRecognizedPrincipal.php
new file mode 100644
index 0000000..c7f99e8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotRecognizedPrincipal.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace OldSabre\DAVACL\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * If a client tried to set a privilege assigned to a non-existant principal,
+ * this exception will be thrown.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NotRecognizedPrincipal extends DAV\Exception\PreconditionFailed {
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {DAV:}recognized-principal element as defined in rfc3744
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS('DAV:','d:recognized-principal');
+        $errorNode->appendChild($np);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotSupportedPrivilege.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotSupportedPrivilege.php
new file mode 100644
index 0000000..7e3adb6
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Exception/NotSupportedPrivilege.php
@@ -0,0 +1,35 @@
+<?php
+
+namespace OldSabre\DAVACL\Exception;
+
+use OldSabre\DAV;
+
+/**
+ * If a client tried to set a privilege that doesn't exist, this exception will
+ * be thrown.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class NotSupportedPrivilege extends DAV\Exception\PreconditionFailed {
+
+    /**
+     * Adds in extra information in the xml response.
+     *
+     * This method adds the {DAV:}not-supported-privilege element as defined in rfc3744
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $errorNode
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $errorNode) {
+
+        $doc = $errorNode->ownerDocument;
+
+        $np = $doc->createElementNS('DAV:','d:not-supported-privilege');
+        $errorNode->appendChild($np);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IACL.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IACL.php
new file mode 100644
index 0000000..7e0508f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IACL.php
@@ -0,0 +1,74 @@
+<?php
+
+namespace OldSabre\DAVACL;
+use OldSabre\DAV;
+
+/**
+ * ACL-enabled node
+ *
+ * If you want to add WebDAV ACL to a node, you must implement this class
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IACL extends DAV\INode {
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    function getOwner();
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    function getGroup();
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    function getACL();
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's as an array argument.
+     *
+     * @param array $acl
+     * @return void
+     */
+    function setACL(array $acl);
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    function getSupportedPrivilegeSet();
+
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipal.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipal.php
new file mode 100644
index 0000000..3e2c95a
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipal.php
@@ -0,0 +1,77 @@
+<?php
+
+namespace OldSabre\DAVACL;
+
+use OldSabre\DAV;
+
+/**
+ * IPrincipal interface
+ *
+ * Implement this interface to define your own principals
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IPrincipal extends DAV\INode {
+
+    /**
+     * Returns a list of alternative urls for a principal
+     *
+     * This can for example be an email address, or ldap url.
+     *
+     * @return array
+     */
+    function getAlternateUriSet();
+
+    /**
+     * Returns the full principal url
+     *
+     * @return string
+     */
+    function getPrincipalUrl();
+
+    /**
+     * Returns the list of group members
+     *
+     * If this principal is a group, this function should return
+     * all member principal uri's for the group.
+     *
+     * @return array
+     */
+    function getGroupMemberSet();
+
+    /**
+     * Returns the list of groups this principal is member of
+     *
+     * If this principal is a member of a (list of) groups, this function
+     * should return a list of principal uri's for it's members.
+     *
+     * @return array
+     */
+    function getGroupMembership();
+
+    /**
+     * Sets a list of group members
+     *
+     * If this principal is a group, this method sets all the group members.
+     * The list of members is always overwritten, never appended to.
+     *
+     * This method should throw an exception if the members could not be set.
+     *
+     * @param array $principals
+     * @return void
+     */
+    function setGroupMemberSet(array $principals);
+
+    /**
+     * Returns the displayname
+     *
+     * This should be a human readable name for the principal.
+     * If none is available, return the nodename.
+     *
+     * @return string
+     */
+    function getDisplayName();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipalCollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipalCollection.php
new file mode 100644
index 0000000..13a6c53
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/IPrincipalCollection.php
@@ -0,0 +1,42 @@
+<?php
+
+namespace OldSabre\DAVACL;
+
+use OldSabre\DAV;
+
+/**
+ * Principal Collection interface.
+ *
+ * Implement this interface to ensure that your principal collection can be
+ * searched using the principal-property-search REPORT.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface IPrincipalCollection extends DAV\INode {
+
+    /**
+     * This method is used to search for principals matching a set of
+     * properties.
+     *
+     * This search is specifically used by RFC3744's principal-property-search
+     * REPORT. You should at least allow searching on
+     * http://sabredav.org/ns}email-address.
+     *
+     * The actual search should be a unicode-non-case-sensitive search. The
+     * keys in searchProperties are the WebDAV property names, while the values
+     * are the property values to search on.
+     *
+     * If multiple properties are being searched on, the search should be
+     * AND'ed.
+     *
+     * This method should simply return a list of 'child names', which may be
+     * used to call $this->getChild in the future.
+     *
+     * @param array $searchProperties
+     * @return array
+     */
+    function searchPrincipals(array $searchProperties);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Plugin.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Plugin.php
new file mode 100644
index 0000000..f2cc020
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Plugin.php
@@ -0,0 +1,1402 @@
+<?php
+
+namespace OldSabre\DAVACL;
+use OldSabre\DAV;
+
+/**
+ * SabreDAV ACL Plugin
+ *
+ * This plugin provides functionality to enforce ACL permissions.
+ * ACL is defined in RFC3744.
+ *
+ * In addition it also provides support for the {DAV:}current-user-principal
+ * property, defined in RFC5397 and the {DAV:}expand-property report, as
+ * defined in RFC3253.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Plugin extends DAV\ServerPlugin {
+
+    /**
+     * Recursion constants
+     *
+     * This only checks the base node
+     */
+    const R_PARENT = 1;
+
+    /**
+     * Recursion constants
+     *
+     * This checks every node in the tree
+     */
+    const R_RECURSIVE = 2;
+
+    /**
+     * Recursion constants
+     *
+     * This checks every parentnode in the tree, but not leaf-nodes.
+     */
+    const R_RECURSIVEPARENTS = 3;
+
+    /**
+     * Reference to server object.
+     *
+     * @var OldSabre\DAV\Server
+     */
+    protected $server;
+
+    /**
+     * List of urls containing principal collections.
+     * Modify this if your principals are located elsewhere.
+     *
+     * @var array
+     */
+    public $principalCollectionSet = array(
+        'principals',
+    );
+
+    /**
+     * By default ACL is only enforced for nodes that have ACL support (the
+     * ones that implement IACL). For any other node, access is
+     * always granted.
+     *
+     * To override this behaviour you can turn this setting off. This is useful
+     * if you plan to fully support ACL in the entire tree.
+     *
+     * @var bool
+     */
+    public $allowAccessToNodesWithoutACL = true;
+
+    /**
+     * By default nodes that are inaccessible by the user, can still be seen
+     * in directory listings (PROPFIND on parent with Depth: 1)
+     *
+     * In certain cases it's desirable to hide inaccessible nodes. Setting this
+     * to true will cause these nodes to be hidden from directory listings.
+     *
+     * @var bool
+     */
+    public $hideNodesFromListings = false;
+
+    /**
+     * This string is prepended to the username of the currently logged in
+     * user. This allows the plugin to determine the principal path based on
+     * the username.
+     *
+     * @var string
+     */
+    public $defaultUsernamePath = 'principals';
+
+    /**
+     * This list of properties are the properties a client can search on using
+     * the {DAV:}principal-property-search report.
+     *
+     * The keys are the property names, values are descriptions.
+     *
+     * @var array
+     */
+    public $principalSearchPropertySet = array(
+        '{DAV:}displayname' => 'Display name',
+        '{http://sabredav.org/ns}email-address' => 'Email address',
+    );
+
+    /**
+     * Any principal uri's added here, will automatically be added to the list
+     * of ACL's. They will effectively receive {DAV:}all privileges, as a
+     * protected privilege.
+     *
+     * @var array
+     */
+    public $adminPrincipals = array();
+
+    /**
+     * Returns a list of features added by this plugin.
+     *
+     * This list is used in the response of a HTTP OPTIONS request.
+     *
+     * @return array
+     */
+    public function getFeatures() {
+
+        return array('access-control', 'calendarserver-principal-property-search');
+
+    }
+
+    /**
+     * Returns a list of available methods for a given url
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getMethods($uri) {
+
+        return array('ACL');
+
+    }
+
+    /**
+     * Returns a plugin name.
+     *
+     * Using this name other plugins will be able to access other plugins
+     * using OldSabre\DAV\Server::getPlugin
+     *
+     * @return string
+     */
+    public function getPluginName() {
+
+        return 'acl';
+
+    }
+
+    /**
+     * Returns a list of reports this plugin supports.
+     *
+     * This will be used in the {DAV:}supported-report-set property.
+     * Note that you still need to subscribe to the 'report' event to actually
+     * implement them
+     *
+     * @param string $uri
+     * @return array
+     */
+    public function getSupportedReportSet($uri) {
+
+        return array(
+            '{DAV:}expand-property',
+            '{DAV:}principal-property-search',
+            '{DAV:}principal-search-property-set',
+        );
+
+    }
+
+
+    /**
+     * Checks if the current user has the specified privilege(s).
+     *
+     * You can specify a single privilege, or a list of privileges.
+     * This method will throw an exception if the privilege is not available
+     * and return true otherwise.
+     *
+     * @param string $uri
+     * @param array|string $privileges
+     * @param int $recursion
+     * @param bool $throwExceptions if set to false, this method won't throw exceptions.
+     * @throws OldSabre\DAVACL\Exception\NeedPrivileges
+     * @return bool
+     */
+    public function checkPrivileges($uri, $privileges, $recursion = self::R_PARENT, $throwExceptions = true) {
+
+        if (!is_array($privileges)) $privileges = array($privileges);
+
+        $acl = $this->getCurrentUserPrivilegeSet($uri);
+
+        if (is_null($acl)) {
+            if ($this->allowAccessToNodesWithoutACL) {
+                return true;
+            } else {
+                if ($throwExceptions)
+                    throw new Exception\NeedPrivileges($uri,$privileges);
+                else
+                    return false;
+
+            }
+        }
+
+        $failed = array();
+        foreach($privileges as $priv) {
+
+            if (!in_array($priv, $acl)) {
+                $failed[] = $priv;
+            }
+
+        }
+
+        if ($failed) {
+            if ($throwExceptions)
+                throw new Exception\NeedPrivileges($uri,$failed);
+            else
+                return false;
+        }
+        return true;
+
+    }
+
+    /**
+     * Returns the standard users' principal.
+     *
+     * This is one authorative principal url for the current user.
+     * This method will return null if the user wasn't logged in.
+     *
+     * @return string|null
+     */
+    public function getCurrentUserPrincipal() {
+
+        $authPlugin = $this->server->getPlugin('auth');
+        if (is_null($authPlugin)) return null;
+        /** @var $authPlugin OldSabre\DAV\Auth\Plugin */
+
+        $userName = $authPlugin->getCurrentUser();
+        if (!$userName) return null;
+
+        return $this->defaultUsernamePath . '/' .  $userName;
+
+    }
+
+
+    /**
+     * Returns a list of principals that's associated to the current
+     * user, either directly or through group membership.
+     *
+     * @return array
+     */
+    public function getCurrentUserPrincipals() {
+
+        $currentUser = $this->getCurrentUserPrincipal();
+
+        if (is_null($currentUser)) return array();
+
+        return array_merge(
+            array($currentUser),
+            $this->getPrincipalMembership($currentUser)
+        );
+
+    }
+
+    /**
+     * This array holds a cache for all the principals that are associated with
+     * a single principal.
+     *
+     * @var array
+     */
+    protected $principalMembershipCache = array();
+
+
+    /**
+     * Returns all the principal groups the specified principal is a member of.
+     *
+     * @param string $principal
+     * @return array
+     */
+    public function getPrincipalMembership($mainPrincipal) {
+
+        // First check our cache
+        if (isset($this->principalMembershipCache[$mainPrincipal])) {
+            return $this->principalMembershipCache[$mainPrincipal];
+        }
+
+        $check = array($mainPrincipal);
+        $principals = array();
+
+        while(count($check)) {
+
+            $principal = array_shift($check);
+
+            $node = $this->server->tree->getNodeForPath($principal);
+            if ($node instanceof IPrincipal) {
+                foreach($node->getGroupMembership() as $groupMember) {
+
+                    if (!in_array($groupMember, $principals)) {
+
+                        $check[] = $groupMember;
+                        $principals[] = $groupMember;
+
+                    }
+
+                }
+
+            }
+
+        }
+
+        // Store the result in the cache
+        $this->principalMembershipCache[$mainPrincipal] = $principals;
+
+        return $principals;
+
+    }
+
+    /**
+     * Returns the supported privilege structure for this ACL plugin.
+     *
+     * See RFC3744 for more details. Currently we default on a simple,
+     * standard structure.
+     *
+     * You can either get the list of privileges by a uri (path) or by
+     * specifying a Node.
+     *
+     * @param string|DAV\INode $node
+     * @return array
+     */
+    public function getSupportedPrivilegeSet($node) {
+
+        if (is_string($node)) {
+            $node = $this->server->tree->getNodeForPath($node);
+        }
+
+        if ($node instanceof IACL) {
+            $result = $node->getSupportedPrivilegeSet();
+
+            if ($result)
+                return $result;
+        }
+
+        return self::getDefaultSupportedPrivilegeSet();
+
+    }
+
+    /**
+     * Returns a fairly standard set of privileges, which may be useful for
+     * other systems to use as a basis.
+     *
+     * @return array
+     */
+    static function getDefaultSupportedPrivilegeSet() {
+
+        return array(
+            'privilege'  => '{DAV:}all',
+            'abstract'   => true,
+            'aggregates' => array(
+                array(
+                    'privilege'  => '{DAV:}read',
+                    'aggregates' => array(
+                        array(
+                            'privilege' => '{DAV:}read-acl',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}read-current-user-privilege-set',
+                            'abstract'  => true,
+                        ),
+                    ),
+                ), // {DAV:}read
+                array(
+                    'privilege'  => '{DAV:}write',
+                    'aggregates' => array(
+                        array(
+                            'privilege' => '{DAV:}write-acl',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}write-properties',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}write-content',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}bind',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}unbind',
+                            'abstract'  => true,
+                        ),
+                        array(
+                            'privilege' => '{DAV:}unlock',
+                            'abstract'  => true,
+                        ),
+                    ),
+                ), // {DAV:}write
+            ),
+        ); // {DAV:}all
+
+    }
+
+    /**
+     * Returns the supported privilege set as a flat list
+     *
+     * This is much easier to parse.
+     *
+     * The returned list will be index by privilege name.
+     * The value is a struct containing the following properties:
+     *   - aggregates
+     *   - abstract
+     *   - concrete
+     *
+     * @param string|DAV\INode $node
+     * @return array
+     */
+    final public function getFlatPrivilegeSet($node) {
+
+        $privs = $this->getSupportedPrivilegeSet($node);
+
+        $flat = array();
+        $this->getFPSTraverse($privs, null, $flat);
+
+        return $flat;
+
+    }
+
+    /**
+     * Traverses the privilege set tree for reordering
+     *
+     * This function is solely used by getFlatPrivilegeSet, and would have been
+     * a closure if it wasn't for the fact I need to support PHP 5.2.
+     *
+     * @param array $priv
+     * @param $concrete
+     * @param array $flat
+     * @return void
+     */
+    final private function getFPSTraverse($priv, $concrete, &$flat) {
+
+        $myPriv = array(
+            'privilege' => $priv['privilege'],
+            'abstract' => isset($priv['abstract']) && $priv['abstract'],
+            'aggregates' => array(),
+            'concrete' => isset($priv['abstract']) && $priv['abstract']?$concrete:$priv['privilege'],
+        );
+
+        if (isset($priv['aggregates']))
+            foreach($priv['aggregates'] as $subPriv) $myPriv['aggregates'][] = $subPriv['privilege'];
+
+        $flat[$priv['privilege']] = $myPriv;
+
+        if (isset($priv['aggregates'])) {
+
+            foreach($priv['aggregates'] as $subPriv) {
+
+                $this->getFPSTraverse($subPriv, $myPriv['concrete'], $flat);
+
+            }
+
+        }
+
+    }
+
+    /**
+     * Returns the full ACL list.
+     *
+     * Either a uri or a DAV\INode may be passed.
+     *
+     * null will be returned if the node doesn't support ACLs.
+     *
+     * @param string|DAV\INode $node
+     * @return array
+     */
+    public function getACL($node) {
+
+        if (is_string($node)) {
+            $node = $this->server->tree->getNodeForPath($node);
+        }
+        if (!$node instanceof IACL) {
+            return null;
+        }
+        $acl = $node->getACL();
+        foreach($this->adminPrincipals as $adminPrincipal) {
+            $acl[] = array(
+                'principal' => $adminPrincipal,
+                'privilege' => '{DAV:}all',
+                'protected' => true,
+            );
+        }
+        return $acl;
+
+    }
+
+    /**
+     * Returns a list of privileges the current user has
+     * on a particular node.
+     *
+     * Either a uri or a DAV\INode may be passed.
+     *
+     * null will be returned if the node doesn't support ACLs.
+     *
+     * @param string|DAV\INode $node
+     * @return array
+     */
+    public function getCurrentUserPrivilegeSet($node) {
+
+        if (is_string($node)) {
+            $node = $this->server->tree->getNodeForPath($node);
+        }
+
+        $acl = $this->getACL($node);
+
+        if (is_null($acl)) return null;
+
+        $principals = $this->getCurrentUserPrincipals();
+
+        $collected = array();
+
+        foreach($acl as $ace) {
+
+            $principal = $ace['principal'];
+
+            switch($principal) {
+
+                case '{DAV:}owner' :
+                    $owner = $node->getOwner();
+                    if ($owner && in_array($owner, $principals)) {
+                        $collected[] = $ace;
+                    }
+                    break;
+
+
+                // 'all' matches for every user
+                case '{DAV:}all' :
+
+                // 'authenticated' matched for every user that's logged in.
+                // Since it's not possible to use ACL while not being logged
+                // in, this is also always true.
+                case '{DAV:}authenticated' :
+                    $collected[] = $ace;
+                    break;
+
+                // 'unauthenticated' can never occur either, so we simply
+                // ignore these.
+                case '{DAV:}unauthenticated' :
+                    break;
+
+                default :
+                    if (in_array($ace['principal'], $principals)) {
+                        $collected[] = $ace;
+                    }
+                    break;
+
+            }
+
+
+        }
+
+        // Now we deduct all aggregated privileges.
+        $flat = $this->getFlatPrivilegeSet($node);
+
+        $collected2 = array();
+        while(count($collected)) {
+
+            $current = array_pop($collected);
+            $collected2[] = $current['privilege'];
+
+            foreach($flat[$current['privilege']]['aggregates'] as $subPriv) {
+                $collected2[] = $subPriv;
+                $collected[] = $flat[$subPriv];
+            }
+
+        }
+
+        return array_values(array_unique($collected2));
+
+    }
+
+    /**
+     * Principal property search
+     *
+     * This method can search for principals matching certain values in
+     * properties.
+     *
+     * This method will return a list of properties for the matched properties.
+     *
+     * @param array $searchProperties    The properties to search on. This is a
+     *                                   key-value list. The keys are property
+     *                                   names, and the values the strings to
+     *                                   match them on.
+     * @param array $requestedProperties This is the list of properties to
+     *                                   return for every match.
+     * @param string $collectionUri      The principal collection to search on.
+     *                                   If this is ommitted, the standard
+     *                                   principal collection-set will be used.
+     * @return array     This method returns an array structure similar to
+     *                  OldSabre\DAV\Server::getPropertiesForPath. Returned
+     *                  properties are index by a HTTP status code.
+     *
+     */
+    public function principalSearch(array $searchProperties, array $requestedProperties, $collectionUri = null) {
+
+        if (!is_null($collectionUri)) {
+            $uris = array($collectionUri);
+        } else {
+            $uris = $this->principalCollectionSet;
+        }
+
+        $lookupResults = array();
+        foreach($uris as $uri) {
+
+            $principalCollection = $this->server->tree->getNodeForPath($uri);
+            if (!$principalCollection instanceof IPrincipalCollection) {
+                // Not a principal collection, we're simply going to ignore
+                // this.
+                continue;
+            }
+
+            $results = $principalCollection->searchPrincipals($searchProperties);
+            foreach($results as $result) {
+                $lookupResults[] = rtrim($uri,'/') . '/' . $result;
+            }
+
+        }
+
+        $matches = array();
+
+        foreach($lookupResults as $lookupResult) {
+
+            list($matches[]) = $this->server->getPropertiesForPath($lookupResult, $requestedProperties, 0);
+
+        }
+
+        return $matches;
+
+    }
+
+    /**
+     * Sets up the plugin
+     *
+     * This method is automatically called by the server class.
+     *
+     * @param DAV\Server $server
+     * @return void
+     */
+    public function initialize(DAV\Server $server) {
+
+        $this->server = $server;
+        $server->subscribeEvent('beforeGetProperties',array($this,'beforeGetProperties'));
+
+        $server->subscribeEvent('beforeMethod', array($this,'beforeMethod'),20);
+        $server->subscribeEvent('beforeBind', array($this,'beforeBind'),20);
+        $server->subscribeEvent('beforeUnbind', array($this,'beforeUnbind'),20);
+        $server->subscribeEvent('updateProperties',array($this,'updateProperties'));
+        $server->subscribeEvent('beforeUnlock', array($this,'beforeUnlock'),20);
+        $server->subscribeEvent('report',array($this,'report'));
+        $server->subscribeEvent('unknownMethod', array($this, 'unknownMethod'));
+
+        array_push($server->protectedProperties,
+            '{DAV:}alternate-URI-set',
+            '{DAV:}principal-URL',
+            '{DAV:}group-membership',
+            '{DAV:}principal-collection-set',
+            '{DAV:}current-user-principal',
+            '{DAV:}supported-privilege-set',
+            '{DAV:}current-user-privilege-set',
+            '{DAV:}acl',
+            '{DAV:}acl-restrictions',
+            '{DAV:}inherited-acl-set',
+            '{DAV:}owner',
+            '{DAV:}group'
+        );
+
+        // Automatically mapping nodes implementing IPrincipal to the
+        // {DAV:}principal resourcetype.
+        $server->resourceTypeMapping['OldSabre\\DAVACL\\IPrincipal'] = '{DAV:}principal';
+
+        // Mapping the group-member-set property to the HrefList property
+        // class.
+        $server->propertyMap['{DAV:}group-member-set'] = 'OldSabre\\DAV\\Property\\HrefList';
+
+    }
+
+
+    /* {{{ Event handlers */
+
+    /**
+     * Triggered before any method is handled
+     *
+     * @param string $method
+     * @param string $uri
+     * @return void
+     */
+    public function beforeMethod($method, $uri) {
+
+        $exists = $this->server->tree->nodeExists($uri);
+
+        // If the node doesn't exists, none of these checks apply
+        if (!$exists) return;
+
+        switch($method) {
+
+            case 'GET' :
+            case 'HEAD' :
+            case 'OPTIONS' :
+                // For these 3 we only need to know if the node is readable.
+                $this->checkPrivileges($uri,'{DAV:}read');
+                break;
+
+            case 'PUT' :
+            case 'LOCK' :
+            case 'UNLOCK' :
+                // This method requires the write-content priv if the node
+                // already exists, and bind on the parent if the node is being
+                // created.
+                // The bind privilege is handled in the beforeBind event.
+                $this->checkPrivileges($uri,'{DAV:}write-content');
+                break;
+
+
+            case 'PROPPATCH' :
+                $this->checkPrivileges($uri,'{DAV:}write-properties');
+                break;
+
+            case 'ACL' :
+                $this->checkPrivileges($uri,'{DAV:}write-acl');
+                break;
+
+            case 'COPY' :
+            case 'MOVE' :
+                // Copy requires read privileges on the entire source tree.
+                // If the target exists write-content normally needs to be
+                // checked, however, we're deleting the node beforehand and
+                // creating a new one after, so this is handled by the
+                // beforeUnbind event.
+                //
+                // The creation of the new node is handled by the beforeBind
+                // event.
+                //
+                // If MOVE is used beforeUnbind will also be used to check if
+                // the sourcenode can be deleted.
+                $this->checkPrivileges($uri,'{DAV:}read',self::R_RECURSIVE);
+
+                break;
+
+        }
+
+    }
+
+    /**
+     * Triggered before a new node is created.
+     *
+     * This allows us to check permissions for any operation that creates a
+     * new node, such as PUT, MKCOL, MKCALENDAR, LOCK, COPY and MOVE.
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function beforeBind($uri) {
+
+        list($parentUri,$nodeName) = DAV\URLUtil::splitPath($uri);
+        $this->checkPrivileges($parentUri,'{DAV:}bind');
+
+    }
+
+    /**
+     * Triggered before a node is deleted
+     *
+     * This allows us to check permissions for any operation that will delete
+     * an existing node.
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function beforeUnbind($uri) {
+
+        list($parentUri,$nodeName) = DAV\URLUtil::splitPath($uri);
+        $this->checkPrivileges($parentUri,'{DAV:}unbind',self::R_RECURSIVEPARENTS);
+
+    }
+
+    /**
+     * Triggered before a node is unlocked.
+     *
+     * @param string $uri
+     * @param DAV\Locks\LockInfo $lock
+     * @TODO: not yet implemented
+     * @return void
+     */
+    public function beforeUnlock($uri, DAV\Locks\LockInfo $lock) {
+
+
+    }
+
+    /**
+     * Triggered before properties are looked up in specific nodes.
+     *
+     * @param string $uri
+     * @param DAV\INode $node
+     * @param array $requestedProperties
+     * @param array $returnedProperties
+     * @TODO really should be broken into multiple methods, or even a class.
+     * @return bool
+     */
+    public function beforeGetProperties($uri, DAV\INode $node, &$requestedProperties, &$returnedProperties) {
+
+        // Checking the read permission
+        if (!$this->checkPrivileges($uri,'{DAV:}read',self::R_PARENT,false)) {
+
+            // User is not allowed to read properties
+            if ($this->hideNodesFromListings) {
+                return false;
+            }
+
+            // Marking all requested properties as '403'.
+            foreach($requestedProperties as $key=>$requestedProperty) {
+                unset($requestedProperties[$key]);
+                $returnedProperties[403][$requestedProperty] = null;
+            }
+            return;
+
+        }
+
+        /* Adding principal properties */
+        if ($node instanceof IPrincipal) {
+
+            if (false !== ($index = array_search('{DAV:}alternate-URI-set', $requestedProperties))) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{DAV:}alternate-URI-set'] = new DAV\Property\HrefList($node->getAlternateUriSet());
+
+            }
+            if (false !== ($index = array_search('{DAV:}principal-URL', $requestedProperties))) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{DAV:}principal-URL'] = new DAV\Property\Href($node->getPrincipalUrl() . '/');
+
+            }
+            if (false !== ($index = array_search('{DAV:}group-member-set', $requestedProperties))) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{DAV:}group-member-set'] = new DAV\Property\HrefList($node->getGroupMemberSet());
+
+            }
+            if (false !== ($index = array_search('{DAV:}group-membership', $requestedProperties))) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{DAV:}group-membership'] = new DAV\Property\HrefList($node->getGroupMembership());
+
+            }
+
+            if (false !== ($index = array_search('{DAV:}displayname', $requestedProperties))) {
+
+                $returnedProperties[200]['{DAV:}displayname'] = $node->getDisplayName();
+
+            }
+
+        }
+        if (false !== ($index = array_search('{DAV:}principal-collection-set', $requestedProperties))) {
+
+            unset($requestedProperties[$index]);
+            $val = $this->principalCollectionSet;
+            // Ensuring all collections end with a slash
+            foreach($val as $k=>$v) $val[$k] = $v . '/';
+            $returnedProperties[200]['{DAV:}principal-collection-set'] = new DAV\Property\HrefList($val);
+
+        }
+        if (false !== ($index = array_search('{DAV:}current-user-principal', $requestedProperties))) {
+
+            unset($requestedProperties[$index]);
+            if ($url = $this->getCurrentUserPrincipal()) {
+                $returnedProperties[200]['{DAV:}current-user-principal'] = new Property\Principal(Property\Principal::HREF, $url . '/');
+            } else {
+                $returnedProperties[200]['{DAV:}current-user-principal'] = new Property\Principal(Property\Principal::UNAUTHENTICATED);
+            }
+
+        }
+        if (false !== ($index = array_search('{DAV:}supported-privilege-set', $requestedProperties))) {
+
+            unset($requestedProperties[$index]);
+            $returnedProperties[200]['{DAV:}supported-privilege-set'] = new Property\SupportedPrivilegeSet($this->getSupportedPrivilegeSet($node));
+
+        }
+        if (false !== ($index = array_search('{DAV:}current-user-privilege-set', $requestedProperties))) {
+
+            if (!$this->checkPrivileges($uri, '{DAV:}read-current-user-privilege-set', self::R_PARENT, false)) {
+                $returnedProperties[403]['{DAV:}current-user-privilege-set'] = null;
+                unset($requestedProperties[$index]);
+            } else {
+                $val = $this->getCurrentUserPrivilegeSet($node);
+                if (!is_null($val)) {
+                    unset($requestedProperties[$index]);
+                    $returnedProperties[200]['{DAV:}current-user-privilege-set'] = new Property\CurrentUserPrivilegeSet($val);
+                }
+            }
+
+        }
+
+        /* The ACL property contains all the permissions */
+        if (false !== ($index = array_search('{DAV:}acl', $requestedProperties))) {
+
+            if (!$this->checkPrivileges($uri, '{DAV:}read-acl', self::R_PARENT, false)) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[403]['{DAV:}acl'] = null;
+
+            } else {
+
+                $acl = $this->getACL($node);
+                if (!is_null($acl)) {
+                    unset($requestedProperties[$index]);
+                    $returnedProperties[200]['{DAV:}acl'] = new Property\Acl($this->getACL($node));
+                }
+
+            }
+
+        }
+
+        /* The acl-restrictions property contains information on how privileges
+         * must behave.
+         */
+        if (false !== ($index = array_search('{DAV:}acl-restrictions', $requestedProperties))) {
+            unset($requestedProperties[$index]);
+            $returnedProperties[200]['{DAV:}acl-restrictions'] = new Property\AclRestrictions();
+        }
+
+        /* Adding ACL properties */
+        if ($node instanceof IACL) {
+
+            if (false !== ($index = array_search('{DAV:}owner', $requestedProperties))) {
+
+                unset($requestedProperties[$index]);
+                $returnedProperties[200]['{DAV:}owner'] = new DAV\Property\Href($node->getOwner() . '/');
+
+            }
+
+        }
+
+    }
+
+    /**
+     * This method intercepts PROPPATCH methods and make sure the
+     * group-member-set is updated correctly.
+     *
+     * @param array $propertyDelta
+     * @param array $result
+     * @param DAV\INode $node
+     * @return bool
+     */
+    public function updateProperties(&$propertyDelta, &$result, DAV\INode $node) {
+
+        if (!array_key_exists('{DAV:}group-member-set', $propertyDelta))
+            return;
+
+        if (is_null($propertyDelta['{DAV:}group-member-set'])) {
+            $memberSet = array();
+        } elseif ($propertyDelta['{DAV:}group-member-set'] instanceof DAV\Property\HrefList) {
+            $memberSet = array_map(
+                array($this->server,'calculateUri'),
+                $propertyDelta['{DAV:}group-member-set']->getHrefs()
+            );
+        } else {
+            throw new DAV\Exception('The group-member-set property MUST be an instance of OldSabre\DAV\Property\HrefList or null');
+        }
+
+        if (!($node instanceof IPrincipal)) {
+            $result[403]['{DAV:}group-member-set'] = null;
+            unset($propertyDelta['{DAV:}group-member-set']);
+
+            // Returning false will stop the updateProperties process
+            return false;
+        }
+
+        $node->setGroupMemberSet($memberSet);
+        // We must also clear our cache, just in case
+
+        $this->principalMembershipCache = array();
+
+        $result[200]['{DAV:}group-member-set'] = null;
+        unset($propertyDelta['{DAV:}group-member-set']);
+
+    }
+
+    /**
+     * This method handles HTTP REPORT requests
+     *
+     * @param string $reportName
+     * @param \DOMNode $dom
+     * @return bool
+     */
+    public function report($reportName, $dom) {
+
+        switch($reportName) {
+
+            case '{DAV:}principal-property-search' :
+                $this->principalPropertySearchReport($dom);
+                return false;
+            case '{DAV:}principal-search-property-set' :
+                $this->principalSearchPropertySetReport($dom);
+                return false;
+            case '{DAV:}expand-property' :
+                $this->expandPropertyReport($dom);
+                return false;
+
+        }
+
+    }
+
+    /**
+     * This event is triggered for any HTTP method that is not known by the
+     * webserver.
+     *
+     * @param string $method
+     * @param string $uri
+     * @return bool
+     */
+    public function unknownMethod($method, $uri) {
+
+        if ($method!=='ACL') return;
+
+        $this->httpACL($uri);
+        return false;
+
+    }
+
+    /**
+     * This method is responsible for handling the 'ACL' event.
+     *
+     * @param string $uri
+     * @return void
+     */
+    public function httpACL($uri) {
+
+        $body = $this->server->httpRequest->getBody(true);
+        $dom = DAV\XMLUtil::loadDOMDocument($body);
+
+        $newAcl =
+            Property\Acl::unserialize($dom->firstChild)
+            ->getPrivileges();
+
+        // Normalizing urls
+        foreach($newAcl as $k=>$newAce) {
+            $newAcl[$k]['principal'] = $this->server->calculateUri($newAce['principal']);
+        }
+
+        $node = $this->server->tree->getNodeForPath($uri);
+
+        if (!($node instanceof IACL)) {
+            throw new DAV\Exception\MethodNotAllowed('This node does not support the ACL method');
+        }
+
+        $oldAcl = $this->getACL($node);
+
+        $supportedPrivileges = $this->getFlatPrivilegeSet($node);
+
+        /* Checking if protected principals from the existing principal set are
+           not overwritten. */
+        foreach($oldAcl as $oldAce) {
+
+            if (!isset($oldAce['protected']) || !$oldAce['protected']) continue;
+
+            $found = false;
+            foreach($newAcl as $newAce) {
+                if (
+                    $newAce['privilege'] === $oldAce['privilege'] &&
+                    $newAce['principal'] === $oldAce['principal'] &&
+                    $newAce['protected']
+                )
+                $found = true;
+            }
+
+            if (!$found)
+                throw new Exception\AceConflict('This resource contained a protected {DAV:}ace, but this privilege did not occur in the ACL request');
+
+        }
+
+        foreach($newAcl as $newAce) {
+
+            // Do we recognize the privilege
+            if (!isset($supportedPrivileges[$newAce['privilege']])) {
+                throw new Exception\NotSupportedPrivilege('The privilege you specified (' . $newAce['privilege'] . ') is not recognized by this server');
+            }
+
+            if ($supportedPrivileges[$newAce['privilege']]['abstract']) {
+                throw new Exception\NoAbstract('The privilege you specified (' . $newAce['privilege'] . ') is an abstract privilege');
+            }
+
+            // Looking up the principal
+            try {
+                $principal = $this->server->tree->getNodeForPath($newAce['principal']);
+            } catch (DAV\Exception\NotFound $e) {
+                throw new Exception\NotRecognizedPrincipal('The specified principal (' . $newAce['principal'] . ') does not exist');
+            }
+            if (!($principal instanceof IPrincipal)) {
+                throw new Exception\NotRecognizedPrincipal('The specified uri (' . $newAce['principal'] . ') is not a principal');
+            }
+
+        }
+        $node->setACL($newAcl);
+
+    }
+
+    /* }}} */
+
+    /* Reports {{{ */
+
+    /**
+     * The expand-property report is defined in RFC3253 section 3-8.
+     *
+     * This report is very similar to a standard PROPFIND. The difference is
+     * that it has the additional ability to look at properties containing a
+     * {DAV:}href element, follow that property and grab additional elements
+     * there.
+     *
+     * Other rfc's, such as ACL rely on this report, so it made sense to put
+     * it in this plugin.
+     *
+     * @param \DOMElement $dom
+     * @return void
+     */
+    protected function expandPropertyReport($dom) {
+
+        $requestedProperties = $this->parseExpandPropertyReportRequest($dom->firstChild->firstChild);
+        $depth = $this->server->getHTTPDepth(0);
+        $requestUri = $this->server->getRequestUri();
+
+        $result = $this->expandProperties($requestUri,$requestedProperties,$depth);
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        $dom->formatOutput = true;
+        $multiStatus = $dom->createElement('d:multistatus');
+        $dom->appendChild($multiStatus);
+
+        // Adding in default namespaces
+        foreach($this->server->xmlNamespaces as $namespace=>$prefix) {
+
+            $multiStatus->setAttribute('xmlns:' . $prefix,$namespace);
+
+        }
+
+        foreach($result as $response) {
+            $response->serialize($this->server, $multiStatus);
+        }
+
+        $xml = $dom->saveXML();
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->sendBody($xml);
+
+    }
+
+    /**
+     * This method is used by expandPropertyReport to parse
+     * out the entire HTTP request.
+     *
+     * @param \DOMElement $node
+     * @return array
+     */
+    protected function parseExpandPropertyReportRequest($node) {
+
+        $requestedProperties = array();
+        do {
+
+            if (DAV\XMLUtil::toClarkNotation($node)!=='{DAV:}property') continue;
+
+            if ($node->firstChild) {
+
+                $children = $this->parseExpandPropertyReportRequest($node->firstChild);
+
+            } else {
+
+                $children = array();
+
+            }
+
+            $namespace = $node->getAttribute('namespace');
+            if (!$namespace) $namespace = 'DAV:';
+
+            $propName = '{'.$namespace.'}' . $node->getAttribute('name');
+            $requestedProperties[$propName] = $children;
+
+        } while ($node = $node->nextSibling);
+
+        return $requestedProperties;
+
+    }
+
+    /**
+     * This method expands all the properties and returns
+     * a list with property values
+     *
+     * @param array $path
+     * @param array $requestedProperties the list of required properties
+     * @param int $depth
+     * @return array
+     */
+    protected function expandProperties($path, array $requestedProperties, $depth) {
+
+        $foundProperties = $this->server->getPropertiesForPath($path, array_keys($requestedProperties), $depth);
+
+        $result = array();
+
+        foreach($foundProperties as $node) {
+
+            foreach($requestedProperties as $propertyName=>$childRequestedProperties) {
+
+                // We're only traversing if sub-properties were requested
+                if(count($childRequestedProperties)===0) continue;
+
+                // We only have to do the expansion if the property was found
+                // and it contains an href element.
+                if (!array_key_exists($propertyName,$node[200])) continue;
+
+                if ($node[200][$propertyName] instanceof DAV\Property\IHref) {
+                    $hrefs = array($node[200][$propertyName]->getHref());
+                } elseif ($node[200][$propertyName] instanceof DAV\Property\HrefList) {
+                    $hrefs = $node[200][$propertyName]->getHrefs();
+                }
+
+                $childProps = array();
+                foreach($hrefs as $href) {
+                    $childProps = array_merge($childProps, $this->expandProperties($href, $childRequestedProperties, 0));
+                }
+                $node[200][$propertyName] = new DAV\Property\ResponseList($childProps);
+
+            }
+            $result[] = new DAV\Property\Response($node['href'], $node);
+
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * principalSearchPropertySetReport
+     *
+     * This method responsible for handing the
+     * {DAV:}principal-search-property-set report. This report returns a list
+     * of properties the client may search on, using the
+     * {DAV:}principal-property-search report.
+     *
+     * @param \DOMDocument $dom
+     * @return void
+     */
+    protected function principalSearchPropertySetReport(\DOMDocument $dom) {
+
+        $httpDepth = $this->server->getHTTPDepth(0);
+        if ($httpDepth!==0) {
+            throw new DAV\Exception\BadRequest('This report is only defined when Depth: 0');
+        }
+
+        if ($dom->firstChild->hasChildNodes())
+            throw new DAV\Exception\BadRequest('The principal-search-property-set report element is not allowed to have child elements');
+
+        $dom = new \DOMDocument('1.0','utf-8');
+        $dom->formatOutput = true;
+        $root = $dom->createElement('d:principal-search-property-set');
+        $dom->appendChild($root);
+        // Adding in default namespaces
+        foreach($this->server->xmlNamespaces as $namespace=>$prefix) {
+
+            $root->setAttribute('xmlns:' . $prefix,$namespace);
+
+        }
+
+        $nsList = $this->server->xmlNamespaces;
+
+        foreach($this->principalSearchPropertySet as $propertyName=>$description) {
+
+            $psp = $dom->createElement('d:principal-search-property');
+            $root->appendChild($psp);
+
+            $prop = $dom->createElement('d:prop');
+            $psp->appendChild($prop);
+
+            $propName = null;
+            preg_match('/^{([^}]*)}(.*)$/',$propertyName,$propName);
+
+            $currentProperty = $dom->createElement($nsList[$propName[1]] . ':' . $propName[2]);
+            $prop->appendChild($currentProperty);
+
+            $descriptionElem = $dom->createElement('d:description');
+            $descriptionElem->setAttribute('xml:lang','en');
+            $descriptionElem->appendChild($dom->createTextNode($description));
+            $psp->appendChild($descriptionElem);
+
+
+        }
+
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->sendStatus(200);
+        $this->server->httpResponse->sendBody($dom->saveXML());
+
+    }
+
+    /**
+     * principalPropertySearchReport
+     *
+     * This method is responsible for handing the
+     * {DAV:}principal-property-search report. This report can be used for
+     * clients to search for groups of principals, based on the value of one
+     * or more properties.
+     *
+     * @param \DOMDocument $dom
+     * @return void
+     */
+    protected function principalPropertySearchReport(\DOMDocument $dom) {
+
+        list($searchProperties, $requestedProperties, $applyToPrincipalCollectionSet) = $this->parsePrincipalPropertySearchReportRequest($dom);
+
+        $uri = null;
+        if (!$applyToPrincipalCollectionSet) {
+            $uri = $this->server->getRequestUri();
+        }
+        $result = $this->principalSearch($searchProperties, $requestedProperties, $uri);
+
+        $prefer = $this->server->getHTTPPRefer();
+
+        $this->server->httpResponse->sendStatus(207);
+        $this->server->httpResponse->setHeader('Content-Type','application/xml; charset=utf-8');
+        $this->server->httpResponse->setHeader('Vary','Brief,Prefer');
+        $this->server->httpResponse->sendBody($this->server->generateMultiStatus($result, $prefer['return-minimal']));
+
+    }
+
+    /**
+     * parsePrincipalPropertySearchReportRequest
+     *
+     * This method parses the request body from a
+     * {DAV:}principal-property-search report.
+     *
+     * This method returns an array with two elements:
+     *  1. an array with properties to search on, and their values
+     *  2. a list of propertyvalues that should be returned for the request.
+     *
+     * @param \DOMDocument $dom
+     * @return array
+     */
+    protected function parsePrincipalPropertySearchReportRequest($dom) {
+
+        $httpDepth = $this->server->getHTTPDepth(0);
+        if ($httpDepth!==0) {
+            throw new DAV\Exception\BadRequest('This report is only defined when Depth: 0');
+        }
+
+        $searchProperties = array();
+
+        $applyToPrincipalCollectionSet = false;
+
+        // Parsing the search request
+        foreach($dom->firstChild->childNodes as $searchNode) {
+
+            if (DAV\XMLUtil::toClarkNotation($searchNode) == '{DAV:}apply-to-principal-collection-set') {
+                $applyToPrincipalCollectionSet = true;
+            }
+
+            if (DAV\XMLUtil::toClarkNotation($searchNode)!=='{DAV:}property-search')
+                continue;
+
+            $propertyName = null;
+            $propertyValue = null;
+
+            foreach($searchNode->childNodes as $childNode) {
+
+                switch(DAV\XMLUtil::toClarkNotation($childNode)) {
+
+                    case '{DAV:}prop' :
+                        $property = DAV\XMLUtil::parseProperties($searchNode);
+                        reset($property);
+                        $propertyName = key($property);
+                        break;
+
+                    case '{DAV:}match' :
+                        $propertyValue = $childNode->textContent;
+                        break;
+
+                }
+
+
+            }
+
+            if (is_null($propertyName) || is_null($propertyValue))
+                throw new DAV\Exception\BadRequest('Invalid search request. propertyname: ' . $propertyName . '. propertvvalue: ' . $propertyValue);
+
+            $searchProperties[$propertyName] = $propertyValue;
+
+        }
+
+        return array($searchProperties, array_keys(DAV\XMLUtil::parseProperties($dom->firstChild)), $applyToPrincipalCollectionSet);
+
+    }
+
+
+    /* }}} */
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Principal.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Principal.php
new file mode 100644
index 0000000..a78733d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Principal.php
@@ -0,0 +1,281 @@
+<?php
+
+namespace OldSabre\DAVACL;
+
+use OldSabre\DAV;
+
+/**
+ * Principal class
+ *
+ * This class is a representation of a simple principal
+ *
+ * Many WebDAV specs require a user to show up in the directory
+ * structure.
+ *
+ * This principal also has basic ACL settings, only allowing the principal
+ * access it's own principal.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Principal extends DAV\Node implements IPrincipal, DAV\IProperties, IACL {
+
+    /**
+     * Struct with principal information.
+     *
+     * @var array
+     */
+    protected $principalProperties;
+
+    /**
+     * Principal backend
+     *
+     * @var PrincipalBackend\BackendInterface
+     */
+    protected $principalBackend;
+
+    /**
+     * Creates the principal object
+     *
+     * @param IPrincipalBackend $principalBackend
+     * @param array $principalProperties
+     */
+    public function __construct(PrincipalBackend\BackendInterface $principalBackend, array $principalProperties = array()) {
+
+        if (!isset($principalProperties['uri'])) {
+            throw new DAV\Exception('The principal properties must at least contain the \'uri\' key');
+        }
+        $this->principalBackend = $principalBackend;
+        $this->principalProperties = $principalProperties;
+
+    }
+
+    /**
+     * Returns the full principal url
+     *
+     * @return string
+     */
+    public function getPrincipalUrl() {
+
+        return $this->principalProperties['uri'];
+
+    }
+
+    /**
+     * Returns a list of alternative urls for a principal
+     *
+     * This can for example be an email address, or ldap url.
+     *
+     * @return array
+     */
+    public function getAlternateUriSet() {
+
+        $uris = array();
+        if (isset($this->principalProperties['{DAV:}alternate-URI-set'])) {
+
+            $uris = $this->principalProperties['{DAV:}alternate-URI-set'];
+
+        }
+
+        if (isset($this->principalProperties['{http://sabredav.org/ns}email-address'])) {
+            $uris[] = 'mailto:' . $this->principalProperties['{http://sabredav.org/ns}email-address'];
+        }
+
+        return array_unique($uris);
+
+    }
+
+    /**
+     * Returns the list of group members
+     *
+     * If this principal is a group, this function should return
+     * all member principal uri's for the group.
+     *
+     * @return array
+     */
+    public function getGroupMemberSet() {
+
+        return $this->principalBackend->getGroupMemberSet($this->principalProperties['uri']);
+
+    }
+
+    /**
+     * Returns the list of groups this principal is member of
+     *
+     * If this principal is a member of a (list of) groups, this function
+     * should return a list of principal uri's for it's members.
+     *
+     * @return array
+     */
+    public function getGroupMembership() {
+
+        return $this->principalBackend->getGroupMemberShip($this->principalProperties['uri']);
+
+    }
+
+
+    /**
+     * Sets a list of group members
+     *
+     * If this principal is a group, this method sets all the group members.
+     * The list of members is always overwritten, never appended to.
+     *
+     * This method should throw an exception if the members could not be set.
+     *
+     * @param array $groupMembers
+     * @return void
+     */
+    public function setGroupMemberSet(array $groupMembers) {
+
+        $this->principalBackend->setGroupMemberSet($this->principalProperties['uri'], $groupMembers);
+
+    }
+
+
+    /**
+     * Returns this principals name.
+     *
+     * @return string
+     */
+    public function getName() {
+
+        $uri = $this->principalProperties['uri'];
+        list(, $name) = DAV\URLUtil::splitPath($uri);
+        return $name;
+
+    }
+
+    /**
+     * Returns the name of the user
+     *
+     * @return string
+     */
+    public function getDisplayName() {
+
+        if (isset($this->principalProperties['{DAV:}displayname'])) {
+            return $this->principalProperties['{DAV:}displayname'];
+        } else {
+            return $this->getName();
+        }
+
+    }
+
+    /**
+     * Returns a list of properties
+     *
+     * @param array $requestedProperties
+     * @return array
+     */
+    public function getProperties($requestedProperties) {
+
+        $newProperties = array();
+        foreach($requestedProperties as $propName) {
+
+            if (isset($this->principalProperties[$propName])) {
+                $newProperties[$propName] = $this->principalProperties[$propName];
+            }
+
+        }
+
+        return $newProperties;
+
+    }
+
+    /**
+     * Updates this principals properties.
+     * 
+     * @param array $mutations
+     * @see OldSabre\DAV\IProperties::updateProperties
+     * @return bool|array
+     */
+    public function updateProperties($mutations) {
+
+        return $this->principalBackend->updatePrincipal($this->principalProperties['uri'], $mutations);
+
+    }
+
+    /**
+     * Returns the owner principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getOwner() {
+
+        return $this->principalProperties['uri'];
+
+
+    }
+
+    /**
+     * Returns a group principal
+     *
+     * This must be a url to a principal, or null if there's no owner
+     *
+     * @return string|null
+     */
+    public function getGroup() {
+
+        return null;
+
+    }
+
+    /**
+     * Returns a list of ACE's for this node.
+     *
+     * Each ACE has the following properties:
+     *   * 'privilege', a string such as {DAV:}read or {DAV:}write. These are
+     *     currently the only supported privileges
+     *   * 'principal', a url to the principal who owns the node
+     *   * 'protected' (optional), indicating that this ACE is not allowed to
+     *      be updated.
+     *
+     * @return array
+     */
+    public function getACL() {
+
+        return array(
+            array(
+                'privilege' => '{DAV:}read',
+                'principal' => $this->getPrincipalUrl(),
+                'protected' => true,
+            ),
+        );
+
+    }
+
+    /**
+     * Updates the ACL
+     *
+     * This method will receive a list of new ACE's.
+     *
+     * @param array $acl
+     * @return void
+     */
+    public function setACL(array $acl) {
+
+        throw new DAV\Exception\MethodNotAllowed('Updating ACLs is not allowed here');
+
+    }
+
+    /**
+     * Returns the list of supported privileges for this node.
+     *
+     * The returned data structure is a list of nested privileges.
+     * See OldSabre\DAVACL\Plugin::getDefaultSupportedPrivilegeSet for a simple
+     * standard structure.
+     *
+     * If null is returned from this method, the default privilege set is used,
+     * which is fine for most common usecases.
+     *
+     * @return array|null
+     */
+    public function getSupportedPrivilegeSet() {
+
+        return null;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/AbstractBackend.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/AbstractBackend.php
new file mode 100644
index 0000000..1be74c7
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/AbstractBackend.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace OldSabre\DAVACL\PrincipalBackend;
+
+/**
+ * Abstract Principal Backend
+ *
+ * Currently this class has no function. It's here for consistency and so we
+ * have a non-bc-breaking way to add a default generic implementation to
+ * functions we may add in the future.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractBackend implements BackendInterface {
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/BackendInterface.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/BackendInterface.php
new file mode 100644
index 0000000..52a00b3
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/BackendInterface.php
@@ -0,0 +1,153 @@
+<?php
+
+namespace OldSabre\DAVACL\PrincipalBackend;
+
+/**
+ * Implement this interface to create your own principal backends.
+ *
+ * Creating backends for principals is entirely optional. You can also
+ * implement OldSabre\DAVACL\IPrincipal directly. This interface is used solely by
+ * OldSabre\DAVACL\AbstractPrincipalCollection.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+interface BackendInterface {
+
+    /**
+     * Returns a list of principals based on a prefix.
+     *
+     * This prefix will often contain something like 'principals'. You are only
+     * expected to return principals that are in this base path.
+     *
+     * You are expected to return at least a 'uri' for every user, you can
+     * return any additional properties if you wish so. Common properties are:
+     *   {DAV:}displayname
+     *   {http://sabredav.org/ns}email-address - This is a custom SabreDAV
+     *     field that's actually injected in a number of other properties. If
+     *     you have an email address, use this property.
+     *
+     * @param string $prefixPath
+     * @return array
+     */
+    function getPrincipalsByPrefix($prefixPath);
+
+    /**
+     * Returns a specific principal, specified by it's path.
+     * The returned structure should be the exact same as from
+     * getPrincipalsByPrefix.
+     *
+     * @param string $path
+     * @return array
+     */
+    function getPrincipalByPath($path);
+
+    /**
+     * Updates one ore more webdav properties on a principal.
+     *
+     * The list of mutations is supplied as an array. Each key in the array is
+     * a propertyname, such as {DAV:}displayname.
+     *
+     * Each value is the actual value to be updated. If a value is null, it
+     * must be deleted.
+     *
+     * This method should be atomic. It must either completely succeed, or
+     * completely fail. Success and failure can simply be returned as 'true' or
+     * 'false'.
+     *
+     * It is also possible to return detailed failure information. In that case
+     * an array such as this should be returned:
+     *
+     * array(
+     *   200 => array(
+     *      '{DAV:}prop1' => null,
+     *   ),
+     *   201 => array(
+     *      '{DAV:}prop2' => null,
+     *   ),
+     *   403 => array(
+     *      '{DAV:}prop3' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}prop4' => null,
+     *   ),
+     * );
+     *
+     * In this previous example prop1 was successfully updated or deleted, and
+     * prop2 was succesfully created.
+     *
+     * prop3 failed to update due to '403 Forbidden' and because of this prop4
+     * also could not be updated with '424 Failed dependency'.
+     *
+     * This last example was actually incorrect. While 200 and 201 could appear
+     * in 1 response, if there's any error (403) the other properties should
+     * always fail with 423 (failed dependency).
+     *
+     * But anyway, if you don't want to scratch your head over this, just
+     * return true or false.
+     *
+     * @param string $path
+     * @param array $mutations
+     * @return array|bool
+     */
+    function updatePrincipal($path, $mutations);
+
+    /**
+     * This method is used to search for principals matching a set of
+     * properties.
+     *
+     * This search is specifically used by RFC3744's principal-property-search
+     * REPORT. You should at least allow searching on
+     * http://sabredav.org/ns}email-address.
+     *
+     * The actual search should be a unicode-non-case-sensitive search. The
+     * keys in searchProperties are the WebDAV property names, while the values
+     * are the property values to search on.
+     *
+     * If multiple properties are being searched on, the search should be
+     * AND'ed.
+     *
+     * This method should simply return an array with full principal uri's.
+     *
+     * If somebody attempted to search on a property the backend does not
+     * support, you should simply return 0 results.
+     *
+     * You can also just return 0 results if you choose to not support
+     * searching at all, but keep in mind that this may stop certain features
+     * from working.
+     *
+     * @param string $prefixPath
+     * @param array $searchProperties
+     * @return array
+     */
+    function searchPrincipals($prefixPath, array $searchProperties);
+
+    /**
+     * Returns the list of members for a group-principal
+     *
+     * @param string $principal
+     * @return array
+     */
+    function getGroupMemberSet($principal);
+
+    /**
+     * Returns the list of groups a principal is a member of
+     *
+     * @param string $principal
+     * @return array
+     */
+    function getGroupMembership($principal);
+
+    /**
+     * Updates the list of group members for a group principal.
+     *
+     * The principals should be passed as a list of uri's.
+     *
+     * @param string $principal
+     * @param array $members
+     * @return void
+     */
+    function setGroupMemberSet($principal, array $members);
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/PDO.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/PDO.php
new file mode 100644
index 0000000..92e8417
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalBackend/PDO.php
@@ -0,0 +1,428 @@
+<?php
+
+namespace OldSabre\DAVACL\PrincipalBackend;
+
+use OldSabre\DAV;
+use OldSabre\DAVACL;
+
+/**
+ * PDO principal backend
+ *
+ *
+ * This backend assumes all principals are in a single collection. The default collection
+ * is 'principals/', but this can be overriden.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PDO extends AbstractBackend {
+
+    /**
+     * pdo
+     *
+     * @var PDO
+     */
+    protected $pdo;
+
+    /**
+     * PDO table name for 'principals'
+     *
+     * @var string
+     */
+    protected $tableName;
+
+    /**
+     * PDO table name for 'group members'
+     *
+     * @var string
+     */
+    protected $groupMembersTableName;
+
+    /**
+     * A list of additional fields to support
+     *
+     * @var array
+     */
+    protected $fieldMap = array(
+
+        /**
+         * This property can be used to display the users' real name.
+         */
+        '{DAV:}displayname' => array(
+            'dbField' => 'displayname',
+        ),
+
+        /**
+         * This property is actually used by the CardDAV plugin, where it gets
+         * mapped to {http://calendarserver.orgi/ns/}me-card.
+         *
+         * The reason we don't straight-up use that property, is because
+         * me-card is defined as a property on the users' addressbook
+         * collection.
+         */
+        '{http://sabredav.org/ns}vcard-url' => array(
+            'dbField' => 'vcardurl',
+        ),
+        /**
+         * This is the users' primary email-address.
+         */
+        '{http://sabredav.org/ns}email-address' => array(
+            'dbField' => 'email',
+        ),
+    );
+
+    /**
+     * Sets up the backend.
+     *
+     * @param PDO $pdo
+     * @param string $tableName
+     * @param string $groupMembersTableName
+     */
+    public function __construct(\PDO $pdo, $tableName = 'principals', $groupMembersTableName = 'groupmembers') {
+
+        $this->pdo = $pdo;
+        $this->tableName = $tableName;
+        $this->groupMembersTableName = $groupMembersTableName;
+
+    }
+
+
+    /**
+     * Returns a list of principals based on a prefix.
+     *
+     * This prefix will often contain something like 'principals'. You are only
+     * expected to return principals that are in this base path.
+     *
+     * You are expected to return at least a 'uri' for every user, you can
+     * return any additional properties if you wish so. Common properties are:
+     *   {DAV:}displayname
+     *   {http://sabredav.org/ns}email-address - This is a custom SabreDAV
+     *     field that's actualy injected in a number of other properties. If
+     *     you have an email address, use this property.
+     *
+     * @param string $prefixPath
+     * @return array
+     */
+    public function getPrincipalsByPrefix($prefixPath) {
+
+        $fields = array(
+            'uri',
+        );
+
+        foreach($this->fieldMap as $key=>$value) {
+            $fields[] = $value['dbField'];
+        }
+        $result = $this->pdo->query('SELECT '.implode(',', $fields).'  FROM '. $this->tableName);
+
+        $principals = array();
+
+        while($row = $result->fetch(\PDO::FETCH_ASSOC)) {
+
+            // Checking if the principal is in the prefix
+            list($rowPrefix) = DAV\URLUtil::splitPath($row['uri']);
+            if ($rowPrefix !== $prefixPath) continue;
+
+            $principal = array(
+                'uri' => $row['uri'],
+            );
+            foreach($this->fieldMap as $key=>$value) {
+                if ($row[$value['dbField']]) {
+                    $principal[$key] = $row[$value['dbField']];
+                }
+            }
+            $principals[] = $principal;
+
+        }
+
+        return $principals;
+
+    }
+
+    /**
+     * Returns a specific principal, specified by it's path.
+     * The returned structure should be the exact same as from
+     * getPrincipalsByPrefix.
+     *
+     * @param string $path
+     * @return array
+     */
+    public function getPrincipalByPath($path) {
+
+        $fields = array(
+            'id',
+            'uri',
+        );
+
+        foreach($this->fieldMap as $key=>$value) {
+            $fields[] = $value['dbField'];
+        }
+        $stmt = $this->pdo->prepare('SELECT '.implode(',', $fields).'  FROM '. $this->tableName . ' WHERE uri = ?');
+        $stmt->execute(array($path));
+
+        $row = $stmt->fetch(\PDO::FETCH_ASSOC);
+        if (!$row) return;
+
+        $principal = array(
+            'id'  => $row['id'],
+            'uri' => $row['uri'],
+        );
+        foreach($this->fieldMap as $key=>$value) {
+            if ($row[$value['dbField']]) {
+                $principal[$key] = $row[$value['dbField']];
+            }
+        }
+        return $principal;
+
+    }
+
+    /**
+     * Updates one ore more webdav properties on a principal.
+     *
+     * The list of mutations is supplied as an array. Each key in the array is
+     * a propertyname, such as {DAV:}displayname.
+     *
+     * Each value is the actual value to be updated. If a value is null, it
+     * must be deleted.
+     *
+     * This method should be atomic. It must either completely succeed, or
+     * completely fail. Success and failure can simply be returned as 'true' or
+     * 'false'.
+     *
+     * It is also possible to return detailed failure information. In that case
+     * an array such as this should be returned:
+     *
+     * array(
+     *   200 => array(
+     *      '{DAV:}prop1' => null,
+     *   ),
+     *   201 => array(
+     *      '{DAV:}prop2' => null,
+     *   ),
+     *   403 => array(
+     *      '{DAV:}prop3' => null,
+     *   ),
+     *   424 => array(
+     *      '{DAV:}prop4' => null,
+     *   ),
+     * );
+     *
+     * In this previous example prop1 was successfully updated or deleted, and
+     * prop2 was succesfully created.
+     *
+     * prop3 failed to update due to '403 Forbidden' and because of this prop4
+     * also could not be updated with '424 Failed dependency'.
+     *
+     * This last example was actually incorrect. While 200 and 201 could appear
+     * in 1 response, if there's any error (403) the other properties should
+     * always fail with 423 (failed dependency).
+     *
+     * But anyway, if you don't want to scratch your head over this, just
+     * return true or false.
+     *
+     * @param string $path
+     * @param array $mutations
+     * @return array|bool
+     */
+    public function updatePrincipal($path, $mutations) {
+
+        $updateAble = array();
+        foreach($mutations as $key=>$value) {
+
+            // We are not aware of this field, we must fail.
+            if (!isset($this->fieldMap[$key])) {
+
+                $response = array(
+                    403 => array(
+                        $key => null,
+                    ),
+                    424 => array(),
+                );
+
+                // Adding the rest to the response as a 424
+                foreach($mutations as $subKey=>$subValue) {
+                    if ($subKey !== $key) {
+                        $response[424][$subKey] = null;
+                    }
+                }
+                return $response;
+            }
+
+            $updateAble[$this->fieldMap[$key]['dbField']] = $value;
+
+        }
+
+        // No fields to update
+        $query = "UPDATE " . $this->tableName . " SET ";
+
+        $first = true;
+        foreach($updateAble as $key => $value) {
+            if (!$first) {
+                $query.= ', ';
+            }
+            $first = false;
+            $query.= "$key = :$key ";
+        }
+        $query.='WHERE uri = :uri';
+        $stmt = $this->pdo->prepare($query);
+        $updateAble['uri'] =  $path;
+        $stmt->execute($updateAble);
+
+        return true;
+
+    }
+
+    /**
+     * This method is used to search for principals matching a set of
+     * properties.
+     *
+     * This search is specifically used by RFC3744's principal-property-search
+     * REPORT. You should at least allow searching on
+     * http://sabredav.org/ns}email-address.
+     *
+     * The actual search should be a unicode-non-case-sensitive search. The
+     * keys in searchProperties are the WebDAV property names, while the values
+     * are the property values to search on.
+     *
+     * If multiple properties are being searched on, the search should be
+     * AND'ed.
+     *
+     * This method should simply return an array with full principal uri's.
+     *
+     * If somebody attempted to search on a property the backend does not
+     * support, you should simply return 0 results.
+     *
+     * You can also just return 0 results if you choose to not support
+     * searching at all, but keep in mind that this may stop certain features
+     * from working.
+     *
+     * @param string $prefixPath
+     * @param array $searchProperties
+     * @return array
+     */
+    public function searchPrincipals($prefixPath, array $searchProperties) {
+
+        $query = 'SELECT uri FROM ' . $this->tableName . ' WHERE 1=1 ';
+        $values = array();
+        foreach($searchProperties as $property => $value) {
+
+            switch($property) {
+
+                case '{DAV:}displayname' :
+                    $query.=' AND displayname LIKE ?';
+                    $values[] = '%' . $value . '%';
+                    break;
+                case '{http://sabredav.org/ns}email-address' :
+                    $query.=' AND email LIKE ?';
+                    $values[] = '%' . $value . '%';
+                    break;
+                default :
+                    // Unsupported property
+                    return array();
+
+            }
+
+        }
+        $stmt = $this->pdo->prepare($query);
+        $stmt->execute($values);
+
+        $principals = array();
+        while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+
+            // Checking if the principal is in the prefix
+            list($rowPrefix) = DAV\URLUtil::splitPath($row['uri']);
+            if ($rowPrefix !== $prefixPath) continue;
+
+            $principals[] = $row['uri'];
+
+        }
+
+        return $principals;
+
+    }
+
+    /**
+     * Returns the list of members for a group-principal
+     *
+     * @param string $principal
+     * @return array
+     */
+    public function getGroupMemberSet($principal) {
+
+        $principal = $this->getPrincipalByPath($principal);
+        if (!$principal) throw new DAV\Exception('Principal not found');
+
+        $stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM '.$this->groupMembersTableName.' AS groupmembers LEFT JOIN '.$this->tableName.' AS principals ON groupmembers.member_id = principals.id WHERE groupmembers.principal_id = ?');
+        $stmt->execute(array($principal['id']));
+
+        $result = array();
+        while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+            $result[] = $row['uri'];
+        }
+        return $result;
+
+    }
+
+    /**
+     * Returns the list of groups a principal is a member of
+     *
+     * @param string $principal
+     * @return array
+     */
+    public function getGroupMembership($principal) {
+
+        $principal = $this->getPrincipalByPath($principal);
+        if (!$principal) throw new DAV\Exception('Principal not found');
+
+        $stmt = $this->pdo->prepare('SELECT principals.uri as uri FROM '.$this->groupMembersTableName.' AS groupmembers LEFT JOIN '.$this->tableName.' AS principals ON groupmembers.principal_id = principals.id WHERE groupmembers.member_id = ?');
+        $stmt->execute(array($principal['id']));
+
+        $result = array();
+        while ($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+            $result[] = $row['uri'];
+        }
+        return $result;
+
+    }
+
+    /**
+     * Updates the list of group members for a group principal.
+     *
+     * The principals should be passed as a list of uri's.
+     *
+     * @param string $principal
+     * @param array $members
+     * @return void
+     */
+    public function setGroupMemberSet($principal, array $members) {
+
+        // Grabbing the list of principal id's.
+        $stmt = $this->pdo->prepare('SELECT id, uri FROM '.$this->tableName.' WHERE uri IN (? ' . str_repeat(', ? ', count($members)) . ');');
+        $stmt->execute(array_merge(array($principal), $members));
+
+        $memberIds = array();
+        $principalId = null;
+
+        while($row = $stmt->fetch(\PDO::FETCH_ASSOC)) {
+            if ($row['uri'] == $principal) {
+                $principalId = $row['id'];
+            } else {
+                $memberIds[] = $row['id'];
+            }
+        }
+        if (!$principalId) throw new DAV\Exception('Principal not found');
+
+        // Wiping out old members
+        $stmt = $this->pdo->prepare('DELETE FROM '.$this->groupMembersTableName.' WHERE principal_id = ?;');
+        $stmt->execute(array($principalId));
+
+        foreach($memberIds as $memberId) {
+
+            $stmt = $this->pdo->prepare('INSERT INTO '.$this->groupMembersTableName.' (principal_id, member_id) VALUES (?, ?);');
+            $stmt->execute(array($principalId, $memberId));
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalCollection.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalCollection.php
new file mode 100644
index 0000000..7cee8dc
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/PrincipalCollection.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace OldSabre\DAVACL;
+
+/**
+ * Principals Collection
+ *
+ * This collection represents a list of users.
+ * The users are instances of OldSabre\DAVACL\Principal
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class PrincipalCollection extends AbstractPrincipalCollection {
+
+    /**
+     * This method returns a node for a principal.
+     *
+     * The passed array contains principal information, and is guaranteed to
+     * at least contain a uri item. Other properties may or may not be
+     * supplied by the authentication backend.
+     *
+     * @param array $principal
+     * @return \OldSabre\DAV\INode
+     */
+    public function getChildForPrincipal(array $principal) {
+
+        return new Principal($this->principalBackend, $principal);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Acl.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Acl.php
new file mode 100644
index 0000000..33f5c2e
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Acl.php
@@ -0,0 +1,211 @@
+<?php
+
+namespace OldSabre\DAVACL\Property;
+
+use OldSabre\DAV;
+
+/**
+ * This class represents the {DAV:}acl property
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Acl extends DAV\Property {
+
+    /**
+     * List of privileges
+     *
+     * @var array
+     */
+    private $privileges;
+
+    /**
+     * Whether or not the server base url is required to be prefixed when
+     * serializing the property.
+     *
+     * @var boolean
+     */
+    private $prefixBaseUrl;
+
+    /**
+     * Constructor
+     *
+     * This object requires a structure similar to the return value from
+     * OldSabre\DAVACL\Plugin::getACL().
+     *
+     * Each privilege is a an array with at least a 'privilege' property, and a
+     * 'principal' property. A privilege may have a 'protected' property as
+     * well.
+     *
+     * The prefixBaseUrl should be set to false, if the supplied principal urls
+     * are already full urls. If this is kept to true, the servers base url
+     * will automatically be prefixed.
+     *
+     * @param bool $prefixBaseUrl
+     * @param array $privileges
+     */
+    public function __construct(array $privileges, $prefixBaseUrl = true) {
+
+        $this->privileges = $privileges;
+        $this->prefixBaseUrl = $prefixBaseUrl;
+
+    }
+
+    /**
+     * Returns the list of privileges for this property
+     *
+     * @return array
+     */
+    public function getPrivileges() {
+
+        return $this->privileges;
+
+    }
+
+    /**
+     * Serializes the property into a DOMElement
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+        foreach($this->privileges as $ace) {
+
+            $this->serializeAce($doc, $node, $ace, $server);
+
+        }
+
+    }
+
+    /**
+     * Unserializes the {DAV:}acl xml element.
+     *
+     * @param \DOMElement $dom
+     * @return Acl
+     */
+    static public function unserialize(\DOMElement $dom) {
+
+        $privileges = array();
+        $xaces = $dom->getElementsByTagNameNS('urn:DAV','ace');
+        for($ii=0; $ii < $xaces->length; $ii++) {
+
+            $xace = $xaces->item($ii);
+            $principal = $xace->getElementsByTagNameNS('urn:DAV','principal');
+            if ($principal->length !== 1) {
+                throw new DAV\Exception\BadRequest('Each {DAV:}ace element must have one {DAV:}principal element');
+            }
+            $principal = Principal::unserialize($principal->item(0));
+
+            switch($principal->getType()) {
+                case Principal::HREF :
+                    $principal = $principal->getHref();
+                    break;
+                case Principal::AUTHENTICATED :
+                    $principal = '{DAV:}authenticated';
+                    break;
+                case Principal::UNAUTHENTICATED :
+                    $principal = '{DAV:}unauthenticated';
+                    break;
+                case Principal::ALL :
+                    $principal = '{DAV:}all';
+                    break;
+
+            }
+
+            $protected = false;
+
+            if ($xace->getElementsByTagNameNS('urn:DAV','protected')->length > 0) {
+                $protected = true;
+            }
+
+            $grants = $xace->getElementsByTagNameNS('urn:DAV','grant');
+            if ($grants->length < 1) {
+                throw new DAV\Exception\NotImplemented('Every {DAV:}ace element must have a {DAV:}grant element. {DAV:}deny is not yet supported');
+            }
+            $grant = $grants->item(0);
+
+            $xprivs = $grant->getElementsByTagNameNS('urn:DAV','privilege');
+            for($jj=0; $jj<$xprivs->length; $jj++) {
+
+                $xpriv = $xprivs->item($jj);
+
+                $privilegeName = null;
+
+                for ($kk=0;$kk<$xpriv->childNodes->length;$kk++) {
+
+                    $childNode = $xpriv->childNodes->item($kk);
+                    if ($t = DAV\XMLUtil::toClarkNotation($childNode)) {
+                        $privilegeName = $t;
+                        break;
+                    }
+                }
+                if (is_null($privilegeName)) {
+                    throw new DAV\Exception\BadRequest('{DAV:}privilege elements must have a privilege element contained within them.');
+                }
+
+                $privileges[] = array(
+                    'principal' => $principal,
+                    'protected' => $protected,
+                    'privilege' => $privilegeName,
+                );
+
+            }
+
+        }
+
+        return new self($privileges);
+
+    }
+
+    /**
+     * Serializes a single access control entry.
+     *
+     * @param \DOMDocument $doc
+     * @param \DOMElement $node
+     * @param array $ace
+     * @param DAV\Server $server
+     * @return void
+     */
+    private function serializeAce($doc,$node,$ace, DAV\Server $server) {
+
+        $xace  = $doc->createElementNS('DAV:','d:ace');
+        $node->appendChild($xace);
+
+        $principal = $doc->createElementNS('DAV:','d:principal');
+        $xace->appendChild($principal);
+        switch($ace['principal']) {
+            case '{DAV:}authenticated' :
+                $principal->appendChild($doc->createElementNS('DAV:','d:authenticated'));
+                break;
+            case '{DAV:}unauthenticated' :
+                $principal->appendChild($doc->createElementNS('DAV:','d:unauthenticated'));
+                break;
+            case '{DAV:}all' :
+                $principal->appendChild($doc->createElementNS('DAV:','d:all'));
+                break;
+            default:
+                $principal->appendChild($doc->createElementNS('DAV:','d:href',($this->prefixBaseUrl?$server->getBaseUri():'') . $ace['principal'] . '/'));
+        }
+
+        $grant = $doc->createElementNS('DAV:','d:grant');
+        $xace->appendChild($grant);
+
+        $privParts = null;
+
+        preg_match('/^{([^}]*)}(.*)$/',$ace['privilege'],$privParts);
+
+        $xprivilege = $doc->createElementNS('DAV:','d:privilege');
+        $grant->appendChild($xprivilege);
+
+        $xprivilege->appendChild($doc->createElementNS($privParts[1],'d:'.$privParts[2]));
+
+        if (isset($ace['protected']) && $ace['protected'])
+            $xace->appendChild($doc->createElement('d:protected'));
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/AclRestrictions.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/AclRestrictions.php
new file mode 100644
index 0000000..f9485ef
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/AclRestrictions.php
@@ -0,0 +1,34 @@
+<?php
+
+namespace OldSabre\DAVACL\Property;
+
+use OldSabre\DAV;
+
+/**
+ * AclRestrictions property
+ *
+ * This property represents {DAV:}acl-restrictions, as defined in RFC3744.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AclRestrictions extends DAV\Property {
+
+    /**
+     * Serializes the property into a DOMElement
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $elem
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $elem) {
+
+        $doc = $elem->ownerDocument;
+
+        $elem->appendChild($doc->createElementNS('DAV:','d:grant-only'));
+        $elem->appendChild($doc->createElementNS('DAV:','d:no-invert'));
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/CurrentUserPrivilegeSet.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/CurrentUserPrivilegeSet.php
new file mode 100644
index 0000000..e364121
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/CurrentUserPrivilegeSet.php
@@ -0,0 +1,124 @@
+<?php
+
+namespace OldSabre\DAVACL\Property;
+
+use OldSabre\DAV;
+
+/**
+ * CurrentUserPrivilegeSet
+ *
+ * This class represents the current-user-privilege-set property. When
+ * requested, it contain all the privileges a user has on a specific node.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class CurrentUserPrivilegeSet extends DAV\Property {
+
+    /**
+     * List of privileges
+     *
+     * @var array
+     */
+    private $privileges;
+
+    /**
+     * Creates the object
+     *
+     * Pass the privileges in clark-notation
+     *
+     * @param array $privileges
+     */
+    public function __construct(array $privileges) {
+
+        $this->privileges = $privileges;
+
+    }
+
+    /**
+     * Serializes the property in the DOM
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+        foreach($this->privileges as $privName) {
+
+            $this->serializePriv($doc,$node,$privName);
+
+        }
+
+    }
+
+    /**
+     * Returns true or false, whether the specified principal appears in the
+     * list.
+     *
+     * @return bool
+     */
+    public function has($privilegeName) {
+
+        return in_array($privilegeName, $this->privileges);
+
+    }
+
+    /**
+     * Serializes one privilege
+     *
+     * @param \DOMDocument $doc
+     * @param \DOMElement $node
+     * @param string $privName
+     * @return void
+     */
+    protected function serializePriv($doc,$node,$privName) {
+
+        $xp  = $doc->createElementNS('DAV:','d:privilege');
+        $node->appendChild($xp);
+
+        $privParts = null;
+        preg_match('/^{([^}]*)}(.*)$/',$privName,$privParts);
+
+        $xp->appendChild($doc->createElementNS($privParts[1],'d:'.$privParts[2]));
+
+    }
+
+    /**
+     * Unserializes the {DAV:}current-user-privilege-set element.
+     *
+     * @param DOMElement $node
+     * @return CurrentUserPrivilegeSet
+     */
+    static public function unserialize(\DOMElement $node) {
+
+        $result = array();
+
+        $xprivs = $node->getElementsByTagNameNS('urn:DAV','privilege');
+
+        for($jj=0; $jj<$xprivs->length; $jj++) {
+
+            $xpriv = $xprivs->item($jj);
+
+            $privilegeName = null;
+
+            for ($kk=0;$kk<$xpriv->childNodes->length;$kk++) {
+
+                $childNode = $xpriv->childNodes->item($kk);
+                if ($t = DAV\XMLUtil::toClarkNotation($childNode)) {
+                    $privilegeName = $t;
+                    break;
+                }
+            }
+
+            $result[] = $privilegeName;
+
+        }
+
+        return new self($result);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Principal.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Principal.php
new file mode 100644
index 0000000..fbf7c1f
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/Principal.php
@@ -0,0 +1,161 @@
+<?php
+
+namespace OldSabre\DAVACL\Property;
+use OldSabre\DAV;
+
+/**
+ * Principal property
+ *
+ * The principal property represents a principal from RFC3744 (ACL).
+ * The property can be used to specify a principal or pseudo principals.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Principal extends DAV\Property implements DAV\Property\IHref {
+
+    /**
+     * To specify a not-logged-in user, use the UNAUTHENTICATED principal
+     */
+    const UNAUTHENTICATED = 1;
+
+    /**
+     * To specify any principal that is logged in, use AUTHENTICATED
+     */
+    const AUTHENTICATED = 2;
+
+    /**
+     * Specific principals can be specified with the HREF
+     */
+    const HREF = 3;
+
+    /**
+     * Everybody, basically
+     */
+    const ALL = 4;
+
+    /**
+     * Principal-type
+     *
+     * Must be one of the UNAUTHENTICATED, AUTHENTICATED or HREF constants.
+     *
+     * @var int
+     */
+    private $type;
+
+    /**
+     * Url to principal
+     *
+     * This value is only used for the HREF principal type.
+     *
+     * @var string
+     */
+    private $href;
+
+    /**
+     * Creates the property.
+     *
+     * The 'type' argument must be one of the type constants defined in this class.
+     *
+     * 'href' is only required for the HREF type.
+     *
+     * @param int $type
+     * @param string|null $href
+     */
+    public function __construct($type, $href = null) {
+
+        $this->type = $type;
+
+        if ($type===self::HREF && is_null($href)) {
+            throw new DAV\Exception('The href argument must be specified for the HREF principal type.');
+        }
+        $this->href = $href;
+
+    }
+
+    /**
+     * Returns the principal type
+     *
+     * @return int
+     */
+    public function getType() {
+
+        return $this->type;
+
+    }
+
+    /**
+     * Returns the principal uri.
+     *
+     * @return string
+     */
+    public function getHref() {
+
+        return $this->href;
+
+    }
+
+    /**
+     * Serializes the property into a DOMElement.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server, \DOMElement $node) {
+
+        $prefix = $server->xmlNamespaces['DAV:'];
+        switch($this->type) {
+
+            case self::UNAUTHENTICATED :
+                $node->appendChild(
+                    $node->ownerDocument->createElement($prefix . ':unauthenticated')
+                );
+                break;
+            case self::AUTHENTICATED :
+                $node->appendChild(
+                    $node->ownerDocument->createElement($prefix . ':authenticated')
+                );
+                break;
+            case self::HREF :
+                $href = $node->ownerDocument->createElement($prefix . ':href');
+                $href->nodeValue = $server->getBaseUri() . DAV\URLUtil::encodePath($this->href);
+                $node->appendChild($href);
+                break;
+
+        }
+
+    }
+
+    /**
+     * Deserializes a DOM element into a property object.
+     *
+     * @param \DOMElement $dom
+     * @return Principal
+     */
+    static public function unserialize(\DOMElement $dom) {
+
+        $parent = $dom->firstChild;
+        while(!DAV\XMLUtil::toClarkNotation($parent)) {
+            $parent = $parent->nextSibling;
+        }
+
+        switch(DAV\XMLUtil::toClarkNotation($parent)) {
+
+            case '{DAV:}unauthenticated' :
+                return new self(self::UNAUTHENTICATED);
+            case '{DAV:}authenticated' :
+                return new self(self::AUTHENTICATED);
+            case '{DAV:}href':
+                return new self(self::HREF, $parent->textContent);
+            case '{DAV:}all':
+                return new self(self::ALL);
+            default :
+                throw new DAV\Exception\BadRequest('Unexpected element (' . DAV\XMLUtil::toClarkNotation($parent) . '). Could not deserialize');
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/SupportedPrivilegeSet.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/SupportedPrivilegeSet.php
new file mode 100644
index 0000000..30d1d06
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Property/SupportedPrivilegeSet.php
@@ -0,0 +1,94 @@
+<?php
+
+namespace OldSabre\DAVACL\Property;
+
+use OldSabre\DAV;
+
+/**
+ * SupportedPrivilegeSet property
+ *
+ * This property encodes the {DAV:}supported-privilege-set property, as defined
+ * in rfc3744. Please consult the rfc for details about it's structure.
+ *
+ * This class expects a structure like the one given from
+ * OldSabre\DAVACL\Plugin::getSupportedPrivilegeSet as the argument in its
+ * constructor.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class SupportedPrivilegeSet extends DAV\Property {
+
+    /**
+     * privileges
+     *
+     * @var array
+     */
+    private $privileges;
+
+    /**
+     * Constructor
+     *
+     * @param array $privileges
+     */
+    public function __construct(array $privileges) {
+
+        $this->privileges = $privileges;
+
+    }
+
+    /**
+     * Serializes the property into a domdocument.
+     *
+     * @param DAV\Server $server
+     * @param \DOMElement $node
+     * @return void
+     */
+    public function serialize(DAV\Server $server,\DOMElement $node) {
+
+        $doc = $node->ownerDocument;
+        $this->serializePriv($doc, $node, $this->privileges);
+
+    }
+
+    /**
+     * Serializes a property
+     *
+     * This is a recursive function.
+     *
+     * @param \DOMDocument $doc
+     * @param \DOMElement $node
+     * @param array $privilege
+     * @return void
+     */
+    private function serializePriv($doc,$node,$privilege) {
+
+        $xsp = $doc->createElementNS('DAV:','d:supported-privilege');
+        $node->appendChild($xsp);
+
+        $xp  = $doc->createElementNS('DAV:','d:privilege');
+        $xsp->appendChild($xp);
+
+        $privParts = null;
+        preg_match('/^{([^}]*)}(.*)$/',$privilege['privilege'],$privParts);
+
+        $xp->appendChild($doc->createElementNS($privParts[1],'d:'.$privParts[2]));
+
+        if (isset($privilege['abstract']) && $privilege['abstract']) {
+            $xsp->appendChild($doc->createElementNS('DAV:','d:abstract'));
+        }
+
+        if (isset($privilege['description'])) {
+            $xsp->appendChild($doc->createElementNS('DAV:','d:description',$privilege['description']));
+        }
+
+        if (isset($privilege['aggregates'])) {
+            foreach($privilege['aggregates'] as $subPrivilege) {
+                $this->serializePriv($doc,$xsp,$subPrivilege);
+            }
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Version.php b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Version.php
new file mode 100644
index 0000000..e674cf2
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/DAVACL/Version.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\DAVACL;
+
+/**
+ * This class contains the SabreDAV version constants.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '1.8.7';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AWSAuth.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AWSAuth.php
new file mode 100644
index 0000000..f080983
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AWSAuth.php
@@ -0,0 +1,227 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP AWS Authentication handler
+ *
+ * Use this class to leverage amazon's AWS authentication header
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class AWSAuth extends AbstractAuth {
+
+    /**
+     * The signature supplied by the HTTP client
+     *
+     * @var string
+     */
+    private $signature = null;
+
+    /**
+     * The accesskey supplied by the HTTP client
+     *
+     * @var string
+     */
+    private $accessKey = null;
+
+    /**
+     * An error code, if any
+     *
+     * This value will be filled with one of the ERR_* constants
+     *
+     * @var int
+     */
+    public $errorCode = 0;
+
+    const ERR_NOAWSHEADER = 1;
+    const ERR_MD5CHECKSUMWRONG = 2;
+    const ERR_INVALIDDATEFORMAT = 3;
+    const ERR_REQUESTTIMESKEWED = 4;
+    const ERR_INVALIDSIGNATURE = 5;
+
+    /**
+     * Gathers all information from the headers
+     *
+     * This method needs to be called prior to anything else.
+     *
+     * @return bool
+     */
+    public function init() {
+
+        $authHeader = $this->httpRequest->getHeader('Authorization');
+        $authHeader = explode(' ',$authHeader);
+
+        if ($authHeader[0]!='AWS' || !isset($authHeader[1])) {
+            $this->errorCode = self::ERR_NOAWSHEADER;
+             return false;
+        }
+
+        list($this->accessKey,$this->signature) = explode(':',$authHeader[1]);
+
+        return true;
+
+    }
+
+    /**
+     * Returns the username for the request
+     *
+     * @return string
+     */
+    public function getAccessKey() {
+
+        return $this->accessKey;
+
+    }
+
+    /**
+     * Validates the signature based on the secretKey
+     *
+     * @param string $secretKey
+     * @return bool
+     */
+    public function validate($secretKey) {
+
+        $contentMD5 = $this->httpRequest->getHeader('Content-MD5');
+
+        if ($contentMD5) {
+            // We need to validate the integrity of the request
+            $body = $this->httpRequest->getBody(true);
+            $this->httpRequest->setBody($body,true);
+
+            if ($contentMD5!=base64_encode(md5($body,true))) {
+                // content-md5 header did not match md5 signature of body
+                $this->errorCode = self::ERR_MD5CHECKSUMWRONG;
+                return false;
+            }
+
+        }
+
+        if (!$requestDate = $this->httpRequest->getHeader('x-amz-date'))
+            $requestDate = $this->httpRequest->getHeader('Date');
+
+        if (!$this->validateRFC2616Date($requestDate))
+            return false;
+
+        $amzHeaders = $this->getAmzHeaders();
+
+        $signature = base64_encode(
+            $this->hmacsha1($secretKey,
+                $this->httpRequest->getMethod() . "\n" .
+                $contentMD5 . "\n" .
+                $this->httpRequest->getHeader('Content-type') . "\n" .
+                $requestDate . "\n" .
+                $amzHeaders .
+                $this->httpRequest->getURI()
+            )
+        );
+
+        if ($this->signature != $signature) {
+
+            $this->errorCode = self::ERR_INVALIDSIGNATURE;
+            return false;
+
+        }
+
+        return true;
+
+    }
+
+
+    /**
+     * Returns an HTTP 401 header, forcing login
+     *
+     * This should be called when username and password are incorrect, or not supplied at all
+     *
+     * @return void
+     */
+    public function requireLogin() {
+
+        $this->httpResponse->setHeader('WWW-Authenticate','AWS');
+        $this->httpResponse->sendStatus(401);
+
+    }
+
+    /**
+     * Makes sure the supplied value is a valid RFC2616 date.
+     *
+     * If we would just use strtotime to get a valid timestamp, we have no way of checking if a
+     * user just supplied the word 'now' for the date header.
+     *
+     * This function also makes sure the Date header is within 15 minutes of the operating
+     * system date, to prevent replay attacks.
+     *
+     * @param string $dateHeader
+     * @return bool
+     */
+    protected function validateRFC2616Date($dateHeader) {
+
+        $date = Util::parseHTTPDate($dateHeader);
+
+        // Unknown format
+        if (!$date) {
+            $this->errorCode = self::ERR_INVALIDDATEFORMAT;
+            return false;
+        }
+
+        $min = new \DateTime('-15 minutes');
+        $max = new \DateTime('+15 minutes');
+
+        // We allow 15 minutes around the current date/time
+        if ($date > $max || $date < $min) {
+            $this->errorCode = self::ERR_REQUESTTIMESKEWED;
+            return false;
+        }
+
+        return $date;
+
+    }
+
+    /**
+     * Returns a list of AMZ headers
+     *
+     * @return string
+     */
+    protected function getAmzHeaders() {
+
+        $amzHeaders = array();
+        $headers = $this->httpRequest->getHeaders();
+        foreach($headers as $headerName => $headerValue) {
+            if (strpos(strtolower($headerName),'x-amz-')===0) {
+                $amzHeaders[strtolower($headerName)] = str_replace(array("\r\n"),array(' '),$headerValue) . "\n";
+            }
+        }
+        ksort($amzHeaders);
+
+        $headerStr = '';
+        foreach($amzHeaders as $h=>$v) {
+            $headerStr.=$h.':'.$v;
+        }
+
+        return $headerStr;
+
+    }
+
+    /**
+     * Generates an HMAC-SHA1 signature
+     *
+     * @param string $key
+     * @param string $message
+     * @return string
+     */
+    private function hmacsha1($key, $message) {
+
+        $blocksize=64;
+        if (strlen($key)>$blocksize)
+            $key=pack('H*', sha1($key));
+        $key=str_pad($key,$blocksize,chr(0x00));
+        $ipad=str_repeat(chr(0x36),$blocksize);
+        $opad=str_repeat(chr(0x5c),$blocksize);
+        $hmac = pack('H*',sha1(($key^$opad).pack('H*',sha1(($key^$ipad).$message))));
+        return $hmac;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AbstractAuth.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AbstractAuth.php
new file mode 100644
index 0000000..584088d
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/AbstractAuth.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP Authentication baseclass
+ *
+ * This class has the common functionality for BasicAuth and DigestAuth
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+abstract class AbstractAuth {
+
+    /**
+     * The realm will be displayed in the dialog boxes
+     *
+     * This identifier can be changed through setRealm()
+     *
+     * @var string
+     */
+    protected $realm = 'SabreDAV';
+
+    /**
+     * HTTP response helper
+     *
+     * @var OldSabre\HTTP\Response
+     */
+    protected $httpResponse;
+
+
+    /**
+     * HTTP request helper
+     *
+     * @var OldSabre\HTTP\Request
+     */
+    protected $httpRequest;
+
+    /**
+     * __construct
+     *
+     */
+    public function __construct() {
+
+        $this->httpResponse = new Response();
+        $this->httpRequest = new Request();
+
+    }
+
+    /**
+     * Sets an alternative HTTP response object
+     *
+     * @param Response $response
+     * @return void
+     */
+    public function setHTTPResponse(Response $response) {
+
+        $this->httpResponse = $response;
+
+    }
+
+    /**
+     * Sets an alternative HTTP request object
+     *
+     * @param Request $request
+     * @return void
+     */
+    public function setHTTPRequest(Request $request) {
+
+        $this->httpRequest = $request;
+
+    }
+
+
+    /**
+     * Sets the realm
+     *
+     * The realm is often displayed in authentication dialog boxes
+     * Commonly an application name displayed here
+     *
+     * @param string $realm
+     * @return void
+     */
+    public function setRealm($realm) {
+
+        $this->realm = $realm;
+
+    }
+
+    /**
+     * Returns the realm
+     *
+     * @return string
+     */
+    public function getRealm() {
+
+        return $this->realm;
+
+    }
+
+    /**
+     * Returns an HTTP 401 header, forcing login
+     *
+     * This should be called when username and password are incorrect, or not supplied at all
+     *
+     * @return void
+     */
+    abstract public function requireLogin();
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/BasicAuth.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/BasicAuth.php
new file mode 100644
index 0000000..e970fb4
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/BasicAuth.php
@@ -0,0 +1,67 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP Basic Authentication handler
+ *
+ * Use this class for easy http authentication setup
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class BasicAuth extends AbstractAuth {
+
+    /**
+     * Returns the supplied username and password.
+     *
+     * The returned array has two values:
+     *   * 0 - username
+     *   * 1 - password
+     *
+     * If nothing was supplied, 'false' will be returned
+     *
+     * @return mixed
+     */
+    public function getUserPass() {
+
+        // Apache and mod_php
+        if (($user = $this->httpRequest->getRawServerValue('PHP_AUTH_USER'))!==null && ($pass = $this->httpRequest->getRawServerValue('PHP_AUTH_PW'))!==null) {
+
+            return array($user,$pass);
+
+        }
+
+        // Most other webservers
+        $auth = $this->httpRequest->getHeader('Authorization');
+
+        // Apache could prefix environment variables with REDIRECT_ when urls
+        // are passed through mod_rewrite
+        if (!$auth) {
+            $auth = $this->httpRequest->getRawServerValue('REDIRECT_HTTP_AUTHORIZATION');
+        }
+
+        if (!$auth) return false;
+
+        if (strpos(strtolower($auth),'basic')!==0) return false;
+
+        return explode(':', base64_decode(substr($auth, 6)),2);
+
+    }
+
+    /**
+     * Returns an HTTP 401 header, forcing login
+     *
+     * This should be called when username and password are incorrect, or not supplied at all
+     *
+     * @return void
+     */
+    public function requireLogin() {
+
+        $this->httpResponse->setHeader('WWW-Authenticate','Basic realm="' . $this->realm . '"');
+        $this->httpResponse->sendStatus(401);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/DigestAuth.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/DigestAuth.php
new file mode 100644
index 0000000..d21a548
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/DigestAuth.php
@@ -0,0 +1,240 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP Digest Authentication handler
+ *
+ * Use this class for easy http digest authentication.
+ * Instructions:
+ *
+ *  1. Create the object
+ *  2. Call the setRealm() method with the realm you plan to use
+ *  3. Call the init method function.
+ *  4. Call the getUserName() function. This function may return false if no
+ *     authentication information was supplied. Based on the username you
+ *     should check your internal database for either the associated password,
+ *     or the so-called A1 hash of the digest.
+ *  5. Call either validatePassword() or validateA1(). This will return true
+ *     or false.
+ *  6. To make sure an authentication prompt is displayed, call the
+ *     requireLogin() method.
+ *
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class DigestAuth extends AbstractAuth {
+
+    /**
+     * These constants are used in setQOP();
+     */
+    const QOP_AUTH = 1;
+    const QOP_AUTHINT = 2;
+
+    protected $nonce;
+    protected $opaque;
+    protected $digestParts;
+    protected $A1;
+    protected $qop = self::QOP_AUTH;
+
+    /**
+     * Initializes the object
+     */
+    public function __construct() {
+
+        $this->nonce = uniqid();
+        $this->opaque = md5($this->realm);
+        parent::__construct();
+
+    }
+
+    /**
+     * Gathers all information from the headers
+     *
+     * This method needs to be called prior to anything else.
+     *
+     * @return void
+     */
+    public function init() {
+
+        $digest = $this->getDigest();
+        $this->digestParts = $this->parseDigest($digest);
+
+    }
+
+    /**
+     * Sets the quality of protection value.
+     *
+     * Possible values are:
+     *   OldSabre\HTTP\DigestAuth::QOP_AUTH
+     *   OldSabre\HTTP\DigestAuth::QOP_AUTHINT
+     *
+     * Multiple values can be specified using logical OR.
+     *
+     * QOP_AUTHINT ensures integrity of the request body, but this is not
+     * supported by most HTTP clients. QOP_AUTHINT also requires the entire
+     * request body to be md5'ed, which can put strains on CPU and memory.
+     *
+     * @param int $qop
+     * @return void
+     */
+    public function setQOP($qop) {
+
+        $this->qop = $qop;
+
+    }
+
+    /**
+     * Validates the user.
+     *
+     * The A1 parameter should be md5($username . ':' . $realm . ':' . $password);
+     *
+     * @param string $A1
+     * @return bool
+     */
+    public function validateA1($A1) {
+
+        $this->A1 = $A1;
+        return $this->validate();
+
+    }
+
+    /**
+     * Validates authentication through a password. The actual password must be provided here.
+     * It is strongly recommended not store the password in plain-text and use validateA1 instead.
+     *
+     * @param string $password
+     * @return bool
+     */
+    public function validatePassword($password) {
+
+        $this->A1 = md5($this->digestParts['username'] . ':' . $this->realm . ':' . $password);
+        return $this->validate();
+
+    }
+
+    /**
+     * Returns the username for the request
+     *
+     * @return string
+     */
+    public function getUsername() {
+
+        return $this->digestParts['username'];
+
+    }
+
+    /**
+     * Validates the digest challenge
+     *
+     * @return bool
+     */
+    protected function validate() {
+
+        $A2 = $this->httpRequest->getMethod() . ':' . $this->digestParts['uri'];
+
+        if ($this->digestParts['qop']=='auth-int') {
+            // Making sure we support this qop value
+            if (!($this->qop & self::QOP_AUTHINT)) return false;
+            // We need to add an md5 of the entire request body to the A2 part of the hash
+            $body = $this->httpRequest->getBody(true);
+            $this->httpRequest->setBody($body,true);
+            $A2 .= ':' . md5($body);
+        } else {
+
+            // We need to make sure we support this qop value
+            if (!($this->qop & self::QOP_AUTH)) return false;
+        }
+
+        $A2 = md5($A2);
+
+        $validResponse = md5("{$this->A1}:{$this->digestParts['nonce']}:{$this->digestParts['nc']}:{$this->digestParts['cnonce']}:{$this->digestParts['qop']}:{$A2}");
+
+        return $this->digestParts['response']==$validResponse;
+
+
+    }
+
+    /**
+     * Returns an HTTP 401 header, forcing login
+     *
+     * This should be called when username and password are incorrect, or not supplied at all
+     *
+     * @return void
+     */
+    public function requireLogin() {
+
+        $qop = '';
+        switch($this->qop) {
+            case self::QOP_AUTH    : $qop = 'auth'; break;
+            case self::QOP_AUTHINT : $qop = 'auth-int'; break;
+            case self::QOP_AUTH | self::QOP_AUTHINT : $qop = 'auth,auth-int'; break;
+        }
+
+        $this->httpResponse->setHeader('WWW-Authenticate','Digest realm="' . $this->realm . '",qop="'.$qop.'",nonce="' . $this->nonce . '",opaque="' . $this->opaque . '"');
+        $this->httpResponse->sendStatus(401);
+
+    }
+
+
+    /**
+     * This method returns the full digest string.
+     *
+     * It should be compatibile with mod_php format and other webservers.
+     *
+     * If the header could not be found, null will be returned
+     *
+     * @return mixed
+     */
+    public function getDigest() {
+
+        // mod_php
+        $digest = $this->httpRequest->getRawServerValue('PHP_AUTH_DIGEST');
+        if ($digest) return $digest;
+
+        // most other servers
+        $digest = $this->httpRequest->getHeader('Authorization');
+
+        // Apache could prefix environment variables with REDIRECT_ when urls
+        // are passed through mod_rewrite
+        if (!$digest) {
+            $digest = $this->httpRequest->getRawServerValue('REDIRECT_HTTP_AUTHORIZATION');
+        }
+
+        if ($digest && strpos(strtolower($digest),'digest')===0) {
+            return substr($digest,7);
+        } else {
+            return null;
+        }
+
+    }
+
+
+    /**
+     * Parses the different pieces of the digest string into an array.
+     *
+     * This method returns false if an incomplete digest was supplied
+     *
+     * @param string $digest
+     * @return mixed
+     */
+    protected function parseDigest($digest) {
+
+        // protect against missing data
+        $needed_parts = array('nonce'=>1, 'nc'=>1, 'cnonce'=>1, 'qop'=>1, 'username'=>1, 'uri'=>1, 'response'=>1);
+        $data = array();
+
+        preg_match_all('@(\w+)=(?:(?:")([^"]+)"|([^\s,$]+))@', $digest, $matches, PREG_SET_ORDER);
+
+        foreach ($matches as $m) {
+            $data[$m[1]] = $m[2] ? $m[2] : $m[3];
+            unset($needed_parts[$m[1]]);
+        }
+
+        return $needed_parts ? false : $data;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Request.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Request.php
new file mode 100644
index 0000000..d4cad65
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Request.php
@@ -0,0 +1,284 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP Request information
+ *
+ * This object can be used to easily access information about an HTTP request.
+ * It can additionally be used to create 'mock' requests.
+ *
+ * This class mostly operates independent, but because of the nature of a single
+ * request per run it can operate as a singleton. For more information check out
+ * the behaviour around 'defaultInputStream'.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Request {
+
+    /**
+     * PHP's $_SERVER data
+     *
+     * @var array
+     */
+    protected $_SERVER;
+
+    /**
+     * PHP's $_POST data
+     *
+     * @var array
+     */
+    protected $_POST;
+
+    /**
+     * The request body, if any.
+     *
+     * This is stored in the form of a stream resource.
+     *
+     * @var resource
+     */
+    protected $body = null;
+
+    /**
+     * This will be set as the 'default' inputStream for a specific HTTP request
+     * We sometimes need to retain, or rebuild this if we need multiple runs
+     * of parsing the original HTTP request.
+     *
+     * @var resource
+     */
+    static $defaultInputStream=null;
+
+    /**
+     * Sets up the object
+     *
+     * The serverData and postData array can be used to override usage of PHP's
+     * global _SERVER and _POST variable respectively.
+     *
+     * @param array $serverData
+     * @param array $postData
+     */
+    public function __construct(array $serverData = null, array $postData = null) {
+
+       if ($serverData) $this->_SERVER = $serverData;
+       else $this->_SERVER =& $_SERVER;
+
+       if ($postData) $this->_POST = $postData;
+       else $this->_POST =& $_POST;
+
+    }
+
+    /**
+     * Returns the value for a specific http header.
+     *
+     * This method returns null if the header did not exist.
+     *
+     * @param string $name
+     * @return string
+     */
+    public function getHeader($name) {
+
+        $name = strtoupper(str_replace(array('-'),array('_'),$name));
+        if (isset($this->_SERVER['HTTP_' . $name])) {
+            return $this->_SERVER['HTTP_' . $name];
+        }
+
+        // There's a few headers that seem to end up in the top-level
+        // server array.
+        switch($name) {
+            case 'CONTENT_TYPE' :
+            case 'CONTENT_LENGTH' :
+                if (isset($this->_SERVER[$name])) {
+                    return $this->_SERVER[$name];
+                }
+                break;
+
+        }
+        return;
+
+    }
+
+    /**
+     * Returns all (known) HTTP headers.
+     *
+     * All headers are converted to lower-case, and additionally all underscores
+     * are automatically converted to dashes
+     *
+     * @return array
+     */
+    public function getHeaders() {
+
+        $hdrs = array();
+        foreach($this->_SERVER as $key=>$value) {
+
+            switch($key) {
+                case 'CONTENT_LENGTH' :
+                case 'CONTENT_TYPE' :
+                    $hdrs[strtolower(str_replace('_','-',$key))] = $value;
+                    break;
+                default :
+                    if (strpos($key,'HTTP_')===0) {
+                        $hdrs[substr(strtolower(str_replace('_','-',$key)),5)] = $value;
+                    }
+                    break;
+            }
+
+        }
+
+        return $hdrs;
+
+    }
+
+    /**
+     * Returns the HTTP request method
+     *
+     * This is for example POST or GET
+     *
+     * @return string
+     */
+    public function getMethod() {
+
+        return $this->_SERVER['REQUEST_METHOD'];
+
+    }
+
+    /**
+     * Returns the requested uri
+     *
+     * @return string
+     */
+    public function getUri() {
+
+        return $this->_SERVER['REQUEST_URI'];
+
+    }
+
+    /**
+     * Will return protocol + the hostname + the uri
+     *
+     * @return string
+     */
+    public function getAbsoluteUri() {
+
+        // Checking if the request was made through HTTPS. The last in line is for IIS
+        $protocol = isset($this->_SERVER['HTTPS']) && ($this->_SERVER['HTTPS']) && ($this->_SERVER['HTTPS']!='off');
+        return ($protocol?'https':'http') . '://'  . $this->getHeader('Host') . $this->getUri();
+
+    }
+
+    /**
+     * Returns everything after the ? from the current url
+     *
+     * @return string
+     */
+    public function getQueryString() {
+
+        return isset($this->_SERVER['QUERY_STRING'])?$this->_SERVER['QUERY_STRING']:'';
+
+    }
+
+    /**
+     * Returns the HTTP request body body
+     *
+     * This method returns a readable stream resource.
+     * If the asString parameter is set to true, a string is sent instead.
+     *
+     * @param bool $asString
+     * @return resource
+     */
+    public function getBody($asString = false) {
+
+        if (is_null($this->body)) {
+            if (!is_null(self::$defaultInputStream)) {
+                $this->body = self::$defaultInputStream;
+            } else {
+                $this->body = fopen('php://input','r');
+                self::$defaultInputStream = $this->body;
+            }
+        }
+        if ($asString) {
+            $body = stream_get_contents($this->body);
+            return $body;
+        } else {
+            return $this->body;
+        }
+
+    }
+
+    /**
+     * Sets the contents of the HTTP request body
+     *
+     * This method can either accept a string, or a readable stream resource.
+     *
+     * If the setAsDefaultInputStream is set to true, it means for this run of the
+     * script the supplied body will be used instead of php://input.
+     *
+     * @param mixed $body
+     * @param bool $setAsDefaultInputStream
+     * @return void
+     */
+    public function setBody($body,$setAsDefaultInputStream = false) {
+
+        if(is_resource($body)) {
+            $this->body = $body;
+        } else {
+
+            $stream = fopen('php://temp','r+');
+            fputs($stream,$body);
+            rewind($stream);
+            // String is assumed
+            $this->body = $stream;
+        }
+        if ($setAsDefaultInputStream) {
+            self::$defaultInputStream = $this->body;
+        }
+
+    }
+
+    /**
+     * Returns PHP's _POST variable.
+     *
+     * The reason this is in a method is so it can be subclassed and
+     * overridden.
+     *
+     * @return array
+     */
+    public function getPostVars() {
+
+        return $this->_POST;
+
+    }
+
+    /**
+     * Returns a specific item from the _SERVER array.
+     *
+     * Do not rely on this feature, it is for internal use only.
+     *
+     * @param string $field
+     * @return string
+     */
+    public function getRawServerValue($field) {
+
+        return isset($this->_SERVER[$field])?$this->_SERVER[$field]:null;
+
+    }
+
+    /**
+     * Returns the HTTP version specified within the request.
+     *
+     * @return string
+     */
+    public function getHTTPVersion() {
+
+        $protocol = $this->getRawServerValue('SERVER_PROTOCOL');
+        if ($protocol==='HTTP/1.0') {
+            return '1.0';
+        } else {
+            return '1.1';
+        }
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Response.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Response.php
new file mode 100644
index 0000000..07009d9
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Response.php
@@ -0,0 +1,175 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * This class represents a HTTP response.
+ *
+ * It contains the HTTP status code, response headers and a message body.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Response {
+
+    /**
+     * The HTTP version to return in the header() line.
+     *
+     * By default you will definitely want this to be HTTP/1.1, but in some
+     * edge cases (most notably pre 1.2 nginx servers acting as a proxy), you
+     * want to force this to 1.0.
+     *
+     * @var string
+     */
+    public $defaultHttpVersion = '1.1';
+
+    /**
+     * Returns a full HTTP status message for an HTTP status code
+     *
+     * @param int $code
+     * @return string
+     */
+    public function getStatusMessage($code, $httpVersion = '1.1') {
+
+        $msg = array(
+            100 => 'Continue',
+            101 => 'Switching Protocols',
+            102 => 'Processing',
+            200 => 'OK',
+            201 => 'Created',
+            202 => 'Accepted',
+            203 => 'Non-Authorative Information',
+            204 => 'No Content',
+            205 => 'Reset Content',
+            206 => 'Partial Content',
+            207 => 'Multi-Status', // RFC 4918
+            208 => 'Already Reported', // RFC 5842
+            226 => 'IM Used', // RFC 3229
+            300 => 'Multiple Choices',
+            301 => 'Moved Permanently',
+            302 => 'Found',
+            303 => 'See Other',
+            304 => 'Not Modified',
+            305 => 'Use Proxy',
+            306 => 'Reserved',
+            307 => 'Temporary Redirect',
+            400 => 'Bad request',
+            401 => 'Unauthorized',
+            402 => 'Payment Required',
+            403 => 'Forbidden',
+            404 => 'Not Found',
+            405 => 'Method Not Allowed',
+            406 => 'Not Acceptable',
+            407 => 'Proxy Authentication Required',
+            408 => 'Request Timeout',
+            409 => 'Conflict',
+            410 => 'Gone',
+            411 => 'Length Required',
+            412 => 'Precondition failed',
+            413 => 'Request Entity Too Large',
+            414 => 'Request-URI Too Long',
+            415 => 'Unsupported Media Type',
+            416 => 'Requested Range Not Satisfiable',
+            417 => 'Expectation Failed',
+            418 => 'I\'m a teapot', // RFC 2324
+            422 => 'Unprocessable Entity', // RFC 4918
+            423 => 'Locked', // RFC 4918
+            424 => 'Failed Dependency', // RFC 4918
+            426 => 'Upgrade required',
+            428 => 'Precondition required', // draft-nottingham-http-new-status
+            429 => 'Too Many Requests', // draft-nottingham-http-new-status
+            431 => 'Request Header Fields Too Large', // draft-nottingham-http-new-status
+            500 => 'Internal Server Error',
+            501 => 'Not Implemented',
+            502 => 'Bad Gateway',
+            503 => 'Service Unavailable',
+            504 => 'Gateway Timeout',
+            505 => 'HTTP Version not supported',
+            506 => 'Variant Also Negotiates',
+            507 => 'Insufficient Storage', // RFC 4918
+            508 => 'Loop Detected', // RFC 5842
+            509 => 'Bandwidth Limit Exceeded', // non-standard
+            510 => 'Not extended',
+            511 => 'Network Authentication Required', // draft-nottingham-http-new-status
+       );
+
+       return 'HTTP/' . $httpVersion . ' ' . $code . ' ' . $msg[$code];
+
+    }
+
+    // @codeCoverageIgnoreStart
+    // We cannot reasonably test header() related methods.
+
+    /**
+     * Sends an HTTP status header to the client.
+     *
+     * @param int $code HTTP status code
+     * @return bool
+     */
+    public function sendStatus($code) {
+
+        if (!headers_sent())
+            return header($this->getStatusMessage($code, $this->defaultHttpVersion));
+        else return false;
+
+    }
+
+    /**
+     * Sets an HTTP header for the response
+     *
+     * @param string $name
+     * @param string $value
+     * @param bool $replace
+     * @return bool
+     */
+    public function setHeader($name, $value, $replace = true) {
+
+        $value = str_replace(array("\r","\n"),array('\r','\n'),$value);
+        if (!headers_sent())
+            return header($name . ': ' . $value, $replace);
+        else return false;
+
+
+    }
+    // @codeCoverageIgnoreEnd
+
+    /**
+     * Sets a bunch of HTTP Headers
+     *
+     * headersnames are specified as keys, value in the array value
+     *
+     * @param array $headers
+     * @return void
+     */
+    public function setHeaders(array $headers) {
+
+        foreach($headers as $key=>$value)
+            $this->setHeader($key, $value);
+
+    }
+
+    /**
+     * Sends the entire response body
+     *
+     * This method can accept either an open filestream, or a string.
+     *
+     * @param mixed $body
+     * @return void
+     */
+    public function sendBody($body) {
+
+        if (is_resource($body)) {
+
+            file_put_contents('php://output', $body);
+
+        } else {
+
+            // We assume a string
+            echo $body;
+
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Util.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Util.php
new file mode 100644
index 0000000..d825ad8
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Util.php
@@ -0,0 +1,82 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * HTTP utility methods
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @author Paul Voegler
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Util {
+
+    /**
+     * Parses a RFC2616-compatible date string
+     *
+     * This method returns false if the date is invalid
+     *
+     * @param string $dateHeader
+     * @return bool|DateTime
+     */
+    static function parseHTTPDate($dateHeader) {
+
+        //RFC 2616 section 3.3.1 Full Date
+        //Only the format is checked, valid ranges are checked by strtotime below
+        $month = '(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)';
+        $weekday = '(Monday|Tuesday|Wednesday|Thursday|Friday|Saturday|Sunday)';
+        $wkday = '(Mon|Tue|Wed|Thu|Fri|Sat|Sun)';
+        $time = '[0-2]\d(\:[0-5]\d){2}';
+        $date3 = $month . ' ([1-3]\d| \d)';
+        $date2 = '[0-3]\d\-' . $month . '\-\d\d';
+        //4-digit year cannot begin with 0 - unix timestamp begins in 1970
+        $date1 = '[0-3]\d ' . $month . ' [1-9]\d{3}';
+
+        //ANSI C's asctime() format
+        //4-digit year cannot begin with 0 - unix timestamp begins in 1970
+        $asctime_date = $wkday . ' ' . $date3 . ' ' . $time . ' [1-9]\d{3}';
+        //RFC 850, obsoleted by RFC 1036
+        $rfc850_date = $weekday . ', ' . $date2 . ' ' . $time . ' GMT';
+        //RFC 822, updated by RFC 1123
+        $rfc1123_date = $wkday . ', ' . $date1 . ' ' . $time . ' GMT';
+        //allowed date formats by RFC 2616
+        $HTTP_date = "($rfc1123_date|$rfc850_date|$asctime_date)";
+
+        //allow for space around the string and strip it
+        $dateHeader = trim($dateHeader, ' ');
+        if (!preg_match('/^' . $HTTP_date . '$/', $dateHeader))
+            return false;
+
+        //append implicit GMT timezone to ANSI C time format
+        if (strpos($dateHeader, ' GMT') === false)
+            $dateHeader .= ' GMT';
+
+
+        $realDate = strtotime($dateHeader);
+        //strtotime can return -1 or false in case of error
+        if ($realDate !== false && $realDate >= 0)
+            return new \DateTime('@' . $realDate, new \DateTimeZone('UTC'));
+
+    }
+
+    /**
+     * Transforms a DateTime object to HTTP's most common date format.
+     *
+     * We're serializing it as the RFC 1123 date, which, for HTTP must be
+     * specified as GMT.
+     *
+     * @param \DateTime $dateTime
+     * @return string
+     */
+    static function toHTTPDate(\DateTime $dateTime) {
+
+        // We need to clone it, as we don't want to affect the existing
+        // DateTime.
+        $dateTime = clone $dateTime;
+        $dateTime->setTimeZone(new \DateTimeZone('GMT'));
+        return $dateTime->format('D, d M Y H:i:s \G\M\T');
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Version.php b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Version.php
new file mode 100644
index 0000000..83d5c59
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/HTTP/Version.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\HTTP;
+
+/**
+ * This class contains the OldSabre\HTTP version constants.
+ *
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '1.8.12';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/lib/OldSabre/autoload.php b/calendar/lib/SabreDAV/lib/OldSabre/autoload.php
new file mode 100644
index 0000000..6882472
--- /dev/null
+++ b/calendar/lib/SabreDAV/lib/OldSabre/autoload.php
@@ -0,0 +1,25 @@
+<?php
+
+/**
+ * SabreDAV's autoloader
+ *
+ * This file is kept for backwards compatibility purposes.
+ * SabreDAV now uses the composer autoloader.
+ *
+ * You should stop including this file, and include 'vendor/autoload.php'
+ * instead.
+ *
+ * @deprecated Will be removed in a future version!
+ * @copyright Copyright (C) 2007-2015 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://sabre.io/license/ Modified BSD License
+ */
+
+/**
+ * We are assuming that the composer autoloader is just 2 directories up.
+ *
+ * This is not the case when sabredav is installed as a dependency. But, in
+ * those cases it's not expected that people will look for this file anyway.
+ */
+
+require __DIR__ . '/../../vendor/autoload.php';