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

32 files changed, 5872 insertions, 0 deletions

diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/ChangeLog b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/ChangeLog
new file mode 100644
index 0000000..c330fa2
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/ChangeLog
@@ -0,0 +1,70 @@
+2.1.0-stable (2013-06-17)
+	* This version is fully backwards compatible with 2.0.*. However, it
+	  contains a few new API's that mimic the VObject 3 API. This allows it to
+	  be used a 'bridge' version.
+	  Specifically, this new version exists so SabreDAV 1.7 and 1.8 can run with
+	  both the 2 and 3 versions of this library.
+	* Added: Property\DateTime::hasTime().
+	* Added: Property\MultiDateTime::hasTime().
+	* Added: Property::getValue().
+	* Added: Document class.
+	* Added: Document::createComponent and Document::createProperty.
+	* Added: Parameter::getValue().
+
+
+2.0.7-stable (2013-03-05)
+	* Fixed: Microsoft re-uses their magic numbers for different timezones,
+	  specifically id 2 for both Sarajevo and Lisbon). A workaround was added
+	  to deal with this.
+
+2.0.6-stable (2013-02-17)
+	* Fixed: The reader now properly parses parameters without a value.
+
+2.0.5-stable (2012-11-05)
+	* Fixed: The FreeBusyGenerator is now properly using the factory methods
+	  for creation of components and properties.
+
+2.0.4-stable (2012-11-02)
+	* Added: Known Lotus Notes / Domino timezone id's.
+
+2.0.3-stable (2012-10-29)
+	* Added: Support for 'GMT+????' format in TZID's.
+	* Added: Support for formats like SystemV/EST5EDT in TZID's.
+	* Fixed: RecurrenceIterator now repairs recurrence rules where UNTIL < DTSTART.
+	* Added: Support for BYHOUR in FREQ=DAILY (@hollodk).
+	* Added: Support for BYHOUR and BYDAY in FREQ=WEEKLY.
+
+2.0.2-stable (2012-10-06)
+	* Added: includes.php file, to load the entire library in one go.
+	* Fixed: A problem with determining alarm triggers for TODO's.
+
+2.0.1-stable (2012-09-22)
+	* Removed: Element class. It wasn't used.
+	* Added: Basic validation and repair methods for broken input data.
+	* Fixed: RecurrenceIterator could infinitely loop when an INTERVAL of 0
+	  was specified.
+	* Added: A cli script that can validate and automatically repair vcards
+	  and iCalendar objects.
+	* Added: A new 'Compound' property, that can automatically split up parts
+	  for properties such as N, ADR, ORG and CATEGORIES.
+	* Added: Splitter classes, that can split up large objects (such as exports)
+	  into individual objects (thanks @DominikTO and @armin-hackmann).
+	* Added: VFREEBUSY component, which allows easily checking wether
+	  timeslots are available.
+	* Added: The Reader class now has a 'FORGIVING' option, which allows it to
+	  parse properties with incorrect characters in the name (at this time, it
+	  just allows underscores).
+	* Added: Also added the 'IGNORE_INVALID_LINES' option, to completely
+	  disregard any invalid lines.
+	* Fixed: A bug in Windows timezone-id mappings for times created in
+	  Greenlands timezone (sorry Greenlanders! I do care!).
+	* Fixed: DTEND was not generated correctly for VFREEBUSY reports.
+	* Fixed: Parser is at least 25% faster with real-world data.
+
+2.0.0-stable (2012-08-08)
+	* VObject is now a separate project from SabreDAV. See the SabreDAV
+	  changelog for version information before 2.0.
+	* New: VObject library now uses PHP 5.3 namespaces.
+	* New: It's possible to specify lists of parameters when constructing
+	  properties.
+	* New: made it easier to construct the FreeBusyGenerator.
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/LICENSE b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/LICENSE
new file mode 100644
index 0000000..628c60c
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/LICENSE
@@ -0,0 +1,27 @@
+Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/)
+
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright notice,
+      this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright notice,
+      this list of conditions and the following disclaimer in the documentation
+      and/or other materials provided with the distribution.
+    * Neither the name Sabre nor the names of its contributors
+      may be used to endorse or promote products derived from this software
+      without specific prior written permission.
+
+    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+    ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+    LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+    CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+    SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+    ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+    POSSIBILITY OF SUCH DAMAGE.
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/README.md b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/README.md
new file mode 100644
index 0000000..e845cec
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/README.md
@@ -0,0 +1,384 @@
+SabreTooth VObject library
+==========================
+
+[![Build Status](https://secure.travis-ci.org/fruux/sabre-vobject.png?branch=master)](http://travis-ci.org/fruux/sabre-vobject)
+
+The VObject library allows you to easily parse and manipulate [iCalendar](https://tools.ietf.org/html/rfc5545)
+and [vCard](https://tools.ietf.org/html/rfc6350) objects using PHP.
+The goal of the VObject library is to create a very complete library, with an easy to use API.
+
+This project is a spin-off from [SabreDAV](http://code.google.com/p/sabredav/), where it has
+been used for several years. The VObject library has 100% unittest coverage.
+
+Installation
+------------
+
+VObject requires PHP 5.3, and should be installed using composer.
+The general composer instructions can be found on the [composer website](http://getcomposer.org/doc/00-intro.md composer website).
+
+After that, just declare the vobject dependency as follows:
+
+```
+"require" : {
+    "sabre/vobject" : "2.0.*"
+}
+```
+
+Then, run `composer.phar update` and you should be good.
+
+Usage
+-----
+
+### Parsing
+
+For our example, we will be using the following vcard:
+
+```
+BEGIN:VCARD
+VERSION:3.0
+PRODID:-//Sabre//Sabre VObject 2.0//EN
+N:Planck;Max;;;
+FN:Max Planck
+EMAIL;TYPE=WORK:mplanck@example.org
+item1.TEL;TYPE=CELL:(+49)3144435678
+item1.X-ABLabel:Private cell
+item2.TEL;TYPE=WORK:(+49)5554564744
+item2.X-ABLabel:Work
+END:VCARD
+```
+
+
+If we want to just print out Max' full name, you can just use property access:
+
+
+```php
+use OldSabre\VObject;
+
+$card = VObject\Reader::read($data);
+echo $card->FN;
+```
+
+### Changing properties
+
+Creating properties is pretty similar. If we like to add his birthday, we just
+set the property:
+
+```php
+$card->BDAY = '1858-04-23';
+```
+
+Note that in the previous example, we're actually updating any existing BDAY that
+may already exist. If we want to add a new property, without overwriting the previous
+we can do this with the `add` method.
+
+```php
+$card->add('EMAIL','max@example.org');
+```
+
+### Parameters
+
+If we want to also specify that this is max' home email addresses, we can do this with
+a third parameter:
+
+```
+$card->add('EMAIL', 'max@example'org', array('type' => 'HOME'));
+```
+
+If we want to read out all the email addresses and their type, this would look something
+like this:
+
+```
+foreach($card->EMAIL as $email) {
+
+    echo $email['TYPE'], ' - ', $email;
+
+}
+```
+
+### Groups
+
+In our example, you can see that the TEL properties are prefixed. These are 'groups' and
+allow you to group multiple related properties together. The group can be any user-defined
+name.
+
+This particular example as generated by the OS X addressbook, which uses the `X-ABLabel`
+to allow the user to specify custom labels for properties. OS X addressbook uses groups
+to tie the label to the property.
+
+The VObject library simply ignores the group if you don't specify it, so this will work:
+
+```php
+foreach($card->TEL as $tel) {
+    echo $tel, "\n";
+}
+```
+
+But if you would like to target a specific group + property, this is possible too:
+
+```php
+echo $card->{'ITEM1.TEL'};
+```
+
+So if you would like to show all the phone numbers, along with their custom label, the
+following syntax is used:
+
+```php
+foreach($card->TEL as $tel) {
+
+    echo $card->{$tel->group . '.X-ABLABEL'}, ": ";
+    echo $tel, "\n";
+
+}
+```
+
+### Serializing / Saving
+
+If you want to generate your updated VObject, you can simply call the serialize() method.
+
+```php
+echo $card->serialize();
+```
+
+### Components
+
+iCalendar, unlike vCards always have sub-components. Where vCards are often just a flat
+list, iCalendar objects tend to have a tree-like structure. For the following paragraphs,
+we will use the following object as the example:
+
+```
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Sabre//Sabre VObject 2.0//EN
+BEGIN:VEVENT
+SUMMARY:Curiosity landing
+DTSTART:20120806T051439Z
+LOCATION:Mars
+END:VEVENT
+END:VCALENDAR
+```
+
+Since events, tasks and journals are always in a sub component, this is also how we
+access them.
+
+```php
+use OldSabre\VObject;
+
+$calendar = VObject\Reader::read($data);
+echo $calendar->VEVENT->SUMMARY;
+```
+
+Adding components to a calendar is done with a factory method:
+
+```php
+$event = VObject\Component::create('VEVENT');
+$calendar->add($event);
+
+$event->SUMMARY = 'Curiosity launch';
+$event->DTSTART = '20111126T150202Z';
+$event->LOCATION = 'Cape Carnival';
+```
+
+By the way.. cloning also works as expected, as the entire structure is cloned along with it:
+
+```php
+$clonedEvent = clone $calendar->VEVENT[0];
+$calendar->add($clonedEvent);
+```
+
+### Date and time handling
+
+If you ever had to deal with iCalendar timezones, you know it can be complicated.
+The way timezones are specified is flawed, which is something I may write an essay about some
+day. VObject does its best to determine the correct timezone. Many standard formats
+have been tested and verified, and special code has been implemented for special-casing
+microsoft generated timezone information, and others.
+
+To get a real php `DateTime` object, you can request this as follows:
+
+```php
+$event = $calendar->VEVENT;
+$start = $event->DTSTART->getDateTime();
+echo $start->format(\DateTime::W3C);
+```
+
+To set the property with a DateTime object, you can use the following syntax:
+
+```php
+$dateTime = new \DateTime('2012-08-07 23:53:00', new DateTimeZone('Europe/Amsterdam'));
+$event->DTSTART->setDateTime($dateTime, VObject\Property\DateTime::DATE);
+```
+
+The second argument specifies the type of date you're setting. The following three
+options exist:
+
+1. `LOCAL` This is a floating time, with no timezone information. This basically specifies that the event happens in whatever the timezone's currently in. This would be encoded as `DTSTART;VALUE=DATE-TIME:20120807235300`
+2. `UTC` This specifies that the time should be encoded as a UTC time. This is encoded as `DTSTART;VALUE=DATE-TIME:20120807205300Z`. Note the extra Z and the fact that it's two hours 'earlier'.
+3. `LOCALTZ` specifies that it's supposed to be encoded in its local timezone. For example `DTSTART;VALUE=DATE-TIME;TZID=Europe/Amsterdam:20120807235300`.
+4. `DATE` This is a date-only, and does not contain the time. In this case this would be encoded as `DTSTART;VALUE=DATE:20120807`.
+
+A few important notes:
+
+* When a `TZID` is specified, there should also be a matching `VTIMEZONE` object with all the timezone information. VObject cannot currently automatically embed this. However, in reality other clients seem to do fine without this information. Yet, for completeness, this will be added in the future.
+* As mentioned, the timezone-determination process may sometimes fail. Report any issues you find, and I'll be quick to add workarounds!
+
+### Recurrence rules
+
+Recurrence rules allow events to recur, for example for a weekly meeting, or an anniversary.
+This is done with the `RRULE` property. The `RRULE` property allows for a LOT of different
+rules. VObject only implements the ones that actually appear in calendar software.
+
+To read more about `RRULE` and all the options, check out [RFC5545](https://tools.ietf.org/html/rfc5545#section-3.8.5).
+VObject supports the following options:
+
+1. `UNTIL` for an end date.
+2. `INTERVAL` for for example "every 2 days".
+3. `COUNT` to stop recurring after x items.
+4. `FREQ=DAILY` to recur every day, and `BYDAY` to limit it to certain days.
+5. `FREQ=WEEKLY` to recur every week, `BYDAY` to expand this to multiple weekdays in every week and `WKST` to specify on which day the week starts.
+6. `FREQ=MONTHLY` to recur every month, `BYMONTHDAY` to expand this to certain days in a month, `BYDAY` to expand it to certain weekdays occuring in a month, and `BYSETPOS` to limit the last two expansions.
+7. `FREQ=YEARLY` to recur every year, `BYMONTH` to expand that to certain months in a year, and `BYDAY` and `BYWEEKDAY` to expand the `BYMONTH` rule even further.
+
+VObject supports the `EXDATE` property for exclusions, but not yet the `RDATE` and `EXRULE` 
+properties. If you're interested in this, please file a github issue, as this will put it
+on my radar.
+
+This is a bit of a complex subject to go in excruciating detail. The
+[RFC](https://tools.ietf.org/html/rfc5545#section-3.8.5) has a lot of examples though.
+
+The hard part is not to write the RRULE, it is to expand them. The most complex and
+hard-to-read code is hidden in this component. Dragons be here.
+
+So, if we have a meeting every 2nd monday of the month, this would be specified as such:
+
+```
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Sabre//Sabre VObject 2.0//EN
+BEGIN:VEVENT
+UID:1102c450-e0d7-11e1-9b23-0800200c9a66
+DTSTART:20120109T140000Z
+RRULE:FREQ=MONTHLY;BYDAY=MO;BYSETPOS=2
+END:VEVENT
+END:VCALENDAR
+```
+
+Note that normally it's not allowed to indent the object like this, but it does make
+it easier to read. This is also the first time I added in a UID, which is required
+for all VEVENT, VTODO and VJOURNAL objects!
+
+To figure out all the meetings for this year, we can use the following syntax:
+
+```php
+use OldSabre\VObject;
+
+$calendar = VObject\Reader::read($data);
+$calendar->expand(new DateTime('2012-01-01'), new DateTime('2012-12-31'));
+```
+
+What the expand method does, is look at its inner events, and expand the recurring
+rule. Our calendar now contains 12 events. The first will have its RRULE stripped,
+and every subsequent VEVENT has the correct meeting date and a `RECURRENCE-ID` set.
+
+This results in something like this:
+
+```
+BEGIN:VCALENDAR
+  VERSION:2.0
+  PRODID:-//Sabre//Sabre VObject 2.0//EN
+  BEGIN:VEVENT
+    UID:1102c450-e0d7-11e1-9b23-0800200c9a66
+    DTSTART:20120109T140000Z
+  END:VEVENT
+  BEGIN:VEVENT
+    UID:1102c450-e0d7-11e1-9b23-0800200c9a66
+    RECURRENCE-ID:20120213T140000Z
+    DTSTART:20120213T140000Z
+  END:VEVENT
+  BEGIN:VEVENT
+    UID:1102c450-e0d7-11e1-9b23-0800200c9a66
+    RECURRENCE-ID:20120312T140000Z
+    DTSTART:20120312T140000Z
+  END:VEVENT
+  ..etc..
+END:VCALENDAR
+```
+
+To show the list of dates, we would do this as such:
+
+```php
+foreach($calendar->VEVENT as $event) {
+    echo $event->DTSTART->getDateTime()->format(\DateTime::ATOM);
+}
+```
+
+In a recurring event, single instances can also be overriden. VObject also takes these
+into consideration. The reason we needed to specify a start and end-date, is because
+some recurrence rules can be 'never ending'.
+
+You should make sure you pick a sane date-range. Because if you pick a 50 year
+time-range, for a daily recurring event; this would result in over 18K objects.
+
+Free-busy report generation
+---------------------------
+
+Some calendaring software can make use of FREEBUSY reports to show when people are
+available.
+
+You can automatically generate these reports from calendars using the `FreeBusyGenerator`.
+
+Example based on our last event:
+
+```php
+// We're giving it the calendar object. It's also possible to specify multiple objects,
+// by setting them as an array.
+//
+// We must also specify a start and end date, because recurring events are expanded.
+$fbGenerator = new VObject\FreeBusyGenerator(
+    new DateTime('2012-01-01'),
+    new DateTime('2012-12-31'),
+    $calendar
+);
+
+// Grabbing the report
+$freebusy = $fbGenerator->result();
+
+// The freebusy report is another VCALENDAR object, so we can serialize it as usual:
+echo $freebusy->serialize();
+```
+
+The output of this script will look like this:
+
+```
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Sabre//Sabre VObject 2.0//EN
+CALSCALE:GREGORIAN
+BEGIN:VFREEBUSY
+DTSTART;VALUE=DATE-TIME:20111231T230000Z
+DTEND;VALUE=DATE-TIME:20111231T230000Z
+DTSTAMP;VALUE=DATE-TIME:20120808T131628Z
+FREEBUSY;FBTYPE=BUSY:20120109T140000Z/20120109T140000Z
+FREEBUSY;FBTYPE=BUSY:20120213T140000Z/20120213T140000Z
+FREEBUSY;FBTYPE=BUSY:20120312T140000Z/20120312T140000Z
+FREEBUSY;FBTYPE=BUSY:20120409T140000Z/20120409T140000Z
+FREEBUSY;FBTYPE=BUSY:20120514T140000Z/20120514T140000Z
+FREEBUSY;FBTYPE=BUSY:20120611T140000Z/20120611T140000Z
+FREEBUSY;FBTYPE=BUSY:20120709T140000Z/20120709T140000Z
+FREEBUSY;FBTYPE=BUSY:20120813T140000Z/20120813T140000Z
+FREEBUSY;FBTYPE=BUSY:20120910T140000Z/20120910T140000Z
+FREEBUSY;FBTYPE=BUSY:20121008T140000Z/20121008T140000Z
+FREEBUSY;FBTYPE=BUSY:20121112T140000Z/20121112T140000Z
+FREEBUSY;FBTYPE=BUSY:20121210T140000Z/20121210T140000Z
+END:VFREEBUSY
+END:VCALENDAR
+```
+
+Support
+-------
+
+Head over to the [SabreDAV mailing list](http://groups.google.com/group/sabredav-discuss) for any questions.
+
+Made at fruux
+-------------
+
+This library is being developed by [fruux](https://fruux.com/). Drop us a line for commercial services or enterprise support.
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/composer.json b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/composer.json
new file mode 100644
index 0000000..0a83d89
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/composer.json
@@ -0,0 +1,31 @@
+{
+    "name": "sabre/vobject",
+    "description" : "The VObject library for PHP allows you to easily parse and manipulate iCalendar and vCard objects",
+    "keywords" : [ "VObject", "iCalendar", "vCard" ],
+    "homepage" : "https://github.com/fruux/sabre-vobject",
+    "license" : "BSD-3-Clause",
+    "require" : {
+        "php"          : ">=5.3.1",
+        "ext-mbstring" : "*"
+    },
+    "authors" : [
+        {
+            "name" : "Evert Pot",
+            "email" : "evert@rooftopsolutions.nl",
+            "homepage" : "http://evertpot.com/",
+            "role" : "Developer"
+        }
+    ],
+    "support" : {
+        "forum" : "https://groups.google.com/group/sabredav-discuss",
+        "source" : "https://github.com/fruux/sabre-vobject"
+    },
+    "autoload" : {
+        "psr-0" : {
+            "OldSabre\\VObject" : "lib/"
+        }
+    },
+    "bin" : [
+        "bin/vobjectvalidate.php"
+    ]
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component.php
new file mode 100644
index 0000000..f4921ac
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component.php
@@ -0,0 +1,405 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * VObject Component
+ *
+ * This class represents a VCALENDAR/VCARD component. A component is for example
+ * VEVENT, VTODO and also VCALENDAR. It starts with BEGIN:COMPONENTNAME and
+ * ends with END:COMPONENTNAME
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Component extends Node {
+
+    /**
+     * Name, for example VEVENT
+     *
+     * @var string
+     */
+    public $name;
+
+    /**
+     * Children properties and components
+     *
+     * @var array
+     */
+    public $children = array();
+
+    /**
+     * If components are added to this map, they will be automatically mapped
+     * to their respective classes, if parsed by the reader or constructed with
+     * the 'create' method.
+     *
+     * @var array
+     */
+    static public $classMap = array(
+        'VALARM'        => 'OldSabre\\VObject\\Component\\VAlarm',
+        'VCALENDAR'     => 'OldSabre\\VObject\\Component\\VCalendar',
+        'VCARD'         => 'OldSabre\\VObject\\Component\\VCard',
+        'VEVENT'        => 'OldSabre\\VObject\\Component\\VEvent',
+        'VJOURNAL'      => 'OldSabre\\VObject\\Component\\VJournal',
+        'VTODO'         => 'OldSabre\\VObject\\Component\\VTodo',
+        'VFREEBUSY'     => 'OldSabre\\VObject\\Component\\VFreeBusy',
+    );
+
+    /**
+     * Creates the new component by name, but in addition will also see if
+     * there's a class mapped to the property name.
+     *
+     * @param string $name
+     * @param string $value
+     * @return Component
+     */
+    static public function create($name, $value = null) {
+
+        $name = strtoupper($name);
+
+        if (isset(self::$classMap[$name])) {
+            return new self::$classMap[$name]($name, $value);
+        } else {
+            return new self($name, $value);
+        }
+
+    }
+
+    /**
+     * Creates a new component.
+     *
+     * By default this object will iterate over its own children, but this can
+     * be overridden with the iterator argument
+     *
+     * @param string $name
+     * @param ElementList $iterator
+     */
+    public function __construct($name, ElementList $iterator = null) {
+
+        $this->name = strtoupper($name);
+        if (!is_null($iterator)) $this->iterator = $iterator;
+
+    }
+
+    /**
+     * Turns the object back into a serialized blob.
+     *
+     * @return string
+     */
+    public function serialize() {
+
+        $str = "BEGIN:" . $this->name . "\r\n";
+
+        /**
+         * Gives a component a 'score' for sorting purposes.
+         *
+         * This is solely used by the childrenSort method.
+         *
+         * A higher score means the item will be lower in the list.
+         * To avoid score collisions, each "score category" has a reasonable
+         * space to accomodate elements. The $key is added to the $score to
+         * preserve the original relative order of elements.
+         *
+         * @param int $key
+         * @param array $array
+         * @return int
+         */
+        $sortScore = function($key, $array) {
+
+            if ($array[$key] instanceof Component) {
+
+                // We want to encode VTIMEZONE first, this is a personal
+                // preference.
+                if ($array[$key]->name === 'VTIMEZONE') {
+                    $score=300000000;
+                    return $score+$key;
+                } else {
+                    $score=400000000;
+                    return $score+$key;
+                }
+            } else {
+                // Properties get encoded first
+                // VCARD version 4.0 wants the VERSION property to appear first
+                if ($array[$key] instanceof Property) {
+                    if ($array[$key]->name === 'VERSION') {
+                        $score=100000000;
+                        return $score+$key;
+                    } else {
+                        // All other properties
+                        $score=200000000;
+                        return $score+$key;
+                    }
+                }
+            }
+
+        };
+
+        $tmp = $this->children;
+        uksort($this->children, function($a, $b) use ($sortScore, $tmp) {
+
+            $sA = $sortScore($a, $tmp);
+            $sB = $sortScore($b, $tmp);
+
+            if ($sA === $sB) return 0;
+
+            return ($sA < $sB) ? -1 : 1;
+
+        });
+
+        foreach($this->children as $child) $str.=$child->serialize();
+        $str.= "END:" . $this->name . "\r\n";
+
+        return $str;
+
+    }
+
+    /**
+     * Adds a new component or element
+     *
+     * You can call this method with the following syntaxes:
+     *
+     * add(Node $node)
+     * add(string $name, $value, array $parameters = array())
+     *
+     * The first version adds an Element
+     * The second adds a property as a string.
+     *
+     * @param mixed $item
+     * @param mixed $itemValue
+     * @return void
+     */
+    public function add($item, $itemValue = null, array $parameters = array()) {
+
+        if ($item instanceof Node) {
+            if (!is_null($itemValue)) {
+                throw new \InvalidArgumentException('The second argument must not be specified, when passing a VObject Node');
+            }
+            $item->parent = $this;
+            $this->children[] = $item;
+        } elseif(is_string($item)) {
+
+            $item = Property::create($item,$itemValue, $parameters);
+            $item->parent = $this;
+            $this->children[] = $item;
+
+        } else {
+
+            throw new \InvalidArgumentException('The first argument must either be a \\OldSabre\\VObject\\Node or a string');
+
+        }
+
+    }
+
+    /**
+     * Returns an iterable list of children
+     *
+     * @return ElementList
+     */
+    public function children() {
+
+        return new ElementList($this->children);
+
+    }
+
+    /**
+     * Returns an array with elements that match the specified name.
+     *
+     * This function is also aware of MIME-Directory groups (as they appear in
+     * vcards). This means that if a property is grouped as "HOME.EMAIL", it
+     * will also be returned when searching for just "EMAIL". If you want to
+     * search for a property in a specific group, you can select on the entire
+     * string ("HOME.EMAIL"). If you want to search on a specific property that
+     * has not been assigned a group, specify ".EMAIL".
+     *
+     * Keys are retained from the 'children' array, which may be confusing in
+     * certain cases.
+     *
+     * @param string $name
+     * @return array
+     */
+    public function select($name) {
+
+        $group = null;
+        $name = strtoupper($name);
+        if (strpos($name,'.')!==false) {
+            list($group,$name) = explode('.', $name, 2);
+        }
+
+        $result = array();
+        foreach($this->children as $key=>$child) {
+
+            if (
+                strtoupper($child->name) === $name &&
+                (is_null($group) || ( $child instanceof Property && strtoupper($child->group) === $group))
+            ) {
+
+                $result[$key] = $child;
+
+            }
+        }
+
+        reset($result);
+        return $result;
+
+    }
+
+    /**
+     * This method only returns a list of sub-components. Properties are
+     * ignored.
+     *
+     * @return array
+     */
+    public function getComponents() {
+
+        $result = array();
+        foreach($this->children as $child) {
+            if ($child instanceof Component) {
+                $result[] = $child;
+            }
+        }
+
+        return $result;
+
+    }
+
+    /**
+     * Validates the node for correctness.
+     *
+     * The following options are supported:
+     *   - Node::REPAIR - If something is broken, and automatic repair may
+     *                    be attempted.
+     *
+     * An array is returned with warnings.
+     *
+     * Every item in the array has the following properties:
+     *    * level - (number between 1 and 3 with severity information)
+     *    * message - (human readable message)
+     *    * node - (reference to the offending node)
+     *
+     * @param int $options
+     * @return array
+     */
+    public function validate($options = 0) {
+
+        $result = array();
+        foreach($this->children as $child) {
+            $result = array_merge($result, $child->validate($options));
+        }
+        return $result;
+
+    }
+
+    /* Magic property accessors {{{ */
+
+    /**
+     * Using 'get' you will either get a property or component,
+     *
+     * If there were no child-elements found with the specified name,
+     * null is returned.
+     *
+     * @param string $name
+     * @return Property
+     */
+    public function __get($name) {
+
+        $matches = $this->select($name);
+        if (count($matches)===0) {
+            return null;
+        } else {
+            $firstMatch = current($matches);
+            /** @var $firstMatch Property */
+            $firstMatch->setIterator(new ElementList(array_values($matches)));
+            return $firstMatch;
+        }
+
+    }
+
+    /**
+     * This method checks if a sub-element with the specified name exists.
+     *
+     * @param string $name
+     * @return bool
+     */
+    public function __isset($name) {
+
+        $matches = $this->select($name);
+        return count($matches)>0;
+
+    }
+
+    /**
+     * Using the setter method you can add properties or subcomponents
+     *
+     * You can either pass a Component, Property
+     * object, or a string to automatically create a Property.
+     *
+     * If the item already exists, it will be removed. If you want to add
+     * a new item with the same name, always use the add() method.
+     *
+     * @param string $name
+     * @param mixed $value
+     * @return void
+     */
+    public function __set($name, $value) {
+
+        $matches = $this->select($name);
+        $overWrite = count($matches)?key($matches):null;
+
+        if ($value instanceof Component || $value instanceof Property) {
+            $value->parent = $this;
+            if (!is_null($overWrite)) {
+                $this->children[$overWrite] = $value;
+            } else {
+                $this->children[] = $value;
+            }
+        } elseif (is_scalar($value)) {
+            $property = Property::create($name,$value);
+            $property->parent = $this;
+            if (!is_null($overWrite)) {
+                $this->children[$overWrite] = $property;
+            } else {
+                $this->children[] = $property;
+            }
+        } else {
+            throw new \InvalidArgumentException('You must pass a \\OldSabre\\VObject\\Component, \\OldSabre\\VObject\\Property or scalar type');
+        }
+
+    }
+
+    /**
+     * Removes all properties and components within this component.
+     *
+     * @param string $name
+     * @return void
+     */
+    public function __unset($name) {
+
+        $matches = $this->select($name);
+        foreach($matches as $k=>$child) {
+
+            unset($this->children[$k]);
+            $child->parent = null;
+
+        }
+
+    }
+
+    /* }}} */
+
+    /**
+     * This method is automatically called when the object is cloned.
+     * Specifically, this will ensure all child elements are also cloned.
+     *
+     * @return void
+     */
+    public function __clone() {
+
+        foreach($this->children as $key=>$child) {
+            $this->children[$key] = clone $child;
+            $this->children[$key]->parent = $this;
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VAlarm.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VAlarm.php
new file mode 100644
index 0000000..e5aed86
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VAlarm.php
@@ -0,0 +1,108 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+use OldSabre\VObject;
+
+/**
+ * VAlarm component
+ *
+ * This component contains some additional functionality specific for VALARMs.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VAlarm extends VObject\Component {
+
+    /**
+     * Returns a DateTime object when this alarm is going to trigger.
+     *
+     * This ignores repeated alarm, only the first trigger is returned.
+     *
+     * @return DateTime
+     */
+    public function getEffectiveTriggerTime() {
+
+        $trigger = $this->TRIGGER;
+        if(!isset($trigger['VALUE']) || strtoupper($trigger['VALUE']) === 'DURATION') {
+            $triggerDuration = VObject\DateTimeParser::parseDuration($this->TRIGGER);
+            $related = (isset($trigger['RELATED']) && strtoupper($trigger['RELATED']) == 'END') ? 'END' : 'START';
+
+            $parentComponent = $this->parent;
+            if ($related === 'START') {
+
+                if ($parentComponent->name === 'VTODO') {
+                    $propName = 'DUE';
+                } else {
+                    $propName = 'DTSTART';
+                }
+
+                $effectiveTrigger = clone $parentComponent->$propName->getDateTime();
+                $effectiveTrigger->add($triggerDuration);
+            } else {
+                if ($parentComponent->name === 'VTODO') {
+                    $endProp = 'DUE';
+                } elseif ($parentComponent->name === 'VEVENT') {
+                    $endProp = 'DTEND';
+                } else {
+                    throw new \LogicException('time-range filters on VALARM components are only supported when they are a child of VTODO or VEVENT');
+                }
+
+                if (isset($parentComponent->$endProp)) {
+                    $effectiveTrigger = clone $parentComponent->$endProp->getDateTime();
+                    $effectiveTrigger->add($triggerDuration);
+                } elseif (isset($parentComponent->DURATION)) {
+                    $effectiveTrigger = clone $parentComponent->DTSTART->getDateTime();
+                    $duration = VObject\DateTimeParser::parseDuration($parentComponent->DURATION);
+                    $effectiveTrigger->add($duration);
+                    $effectiveTrigger->add($triggerDuration);
+                } else {
+                    $effectiveTrigger = clone $parentComponent->DTSTART->getDateTime();
+                    $effectiveTrigger->add($triggerDuration);
+                }
+            }
+        } else {
+            $effectiveTrigger = $trigger->getDateTime();
+        }
+        return $effectiveTrigger;
+
+    }
+
+    /**
+     * Returns true or false depending on if the event falls in the specified
+     * time-range. This is used for filtering purposes.
+     *
+     * The rules used to determine if an event falls within the specified
+     * time-range is based on the CalDAV specification.
+     *
+     * @param \DateTime $start
+     * @param \DateTime $end
+     * @return bool
+     */
+    public function isInTimeRange(\DateTime $start, \DateTime $end) {
+
+        $effectiveTrigger = $this->getEffectiveTriggerTime();
+
+        if (isset($this->DURATION)) {
+            $duration = VObject\DateTimeParser::parseDuration($this->DURATION);
+            $repeat = (string)$this->repeat;
+            if (!$repeat) {
+                $repeat = 1;
+            }
+
+            $period = new \DatePeriod($effectiveTrigger, $duration, (int)$repeat);
+
+            foreach($period as $occurrence) {
+
+                if ($start <= $occurrence && $end > $occurrence) {
+                    return true;
+                }
+            }
+            return false;
+        } else {
+            return ($start <= $effectiveTrigger && $end > $effectiveTrigger);
+        }
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCalendar.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCalendar.php
new file mode 100644
index 0000000..e80871c
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCalendar.php
@@ -0,0 +1,244 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+
+use OldSabre\VObject;
+
+/**
+ * The VCalendar component
+ *
+ * This component adds functionality to a component, specific for a VCALENDAR.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VCalendar extends VObject\Document {
+
+    static $defaultName = 'VCALENDAR';
+
+    /**
+     * Returns a list of all 'base components'. For instance, if an Event has
+     * a recurrence rule, and one instance is overridden, the overridden event
+     * will have the same UID, but will be excluded from this list.
+     *
+     * VTIMEZONE components will always be excluded.
+     *
+     * @param string $componentName filter by component name
+     * @return array
+     */
+    public function getBaseComponents($componentName = null) {
+
+        $components = array();
+        foreach($this->children as $component) {
+
+            if (!$component instanceof VObject\Component)
+                continue;
+
+            if (isset($component->{'RECURRENCE-ID'}))
+                continue;
+
+            if ($componentName && $component->name !== strtoupper($componentName))
+                continue;
+
+            if ($component->name === 'VTIMEZONE')
+                continue;
+
+            $components[] = $component;
+
+        }
+
+        return $components;
+
+    }
+
+    /**
+     * If this calendar object, has events with recurrence rules, this method
+     * can be used to expand the event into multiple sub-events.
+     *
+     * Each event will be stripped from it's recurrence information, and only
+     * the instances of the event in the specified timerange will be left
+     * alone.
+     *
+     * In addition, this method will cause timezone information to be stripped,
+     * and normalized to UTC.
+     *
+     * This method will alter the VCalendar. This cannot be reversed.
+     *
+     * This functionality is specifically used by the CalDAV standard. It is
+     * possible for clients to request expand events, if they are rather simple
+     * clients and do not have the possibility to calculate recurrences.
+     *
+     * @param DateTime $start
+     * @param DateTime $end
+     * @return void
+     */
+    public function expand(\DateTime $start, \DateTime $end) {
+
+        $newEvents = array();
+
+        foreach($this->select('VEVENT') as $key=>$vevent) {
+
+            if (isset($vevent->{'RECURRENCE-ID'})) {
+                unset($this->children[$key]);
+                continue;
+            }
+
+
+            if (!$vevent->rrule) {
+                unset($this->children[$key]);
+                if ($vevent->isInTimeRange($start, $end)) {
+                    $newEvents[] = $vevent;
+                }
+                continue;
+            }
+
+            $uid = (string)$vevent->uid;
+            if (!$uid) {
+                throw new \LogicException('Event did not have a UID!');
+            }
+
+            $it = new VObject\RecurrenceIterator($this, $vevent->uid);
+            $it->fastForward($start);
+
+            while($it->valid() && $it->getDTStart() < $end) {
+
+                if ($it->getDTEnd() > $start) {
+
+                    $newEvents[] = $it->getEventObject();
+
+                }
+                $it->next();
+
+            }
+            unset($this->children[$key]);
+
+        }
+
+        foreach($newEvents as $newEvent) {
+
+            foreach($newEvent->children as $child) {
+                if ($child instanceof VObject\Property\DateTime &&
+                    $child->getDateType() == VObject\Property\DateTime::LOCALTZ) {
+                        $child->setDateTime($child->getDateTime(),VObject\Property\DateTime::UTC);
+                    }
+            }
+
+            $this->add($newEvent);
+
+        }
+
+        // Removing all VTIMEZONE components
+        unset($this->VTIMEZONE);
+
+    }
+
+    /**
+     * Validates the node for correctness.
+     * An array is returned with warnings.
+     *
+     * Every item in the array has the following properties:
+     *    * level - (number between 1 and 3 with severity information)
+     *    * message - (human readable message)
+     *    * node - (reference to the offending node)
+     *
+     * @return array
+     */
+    /*
+    public function validate() {
+
+        $warnings = array();
+
+        $version = $this->select('VERSION');
+        if (count($version)!==1) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'The VERSION property must appear in the VCALENDAR component exactly 1 time',
+                'node' => $this,
+            );
+        } else {
+            if ((string)$this->VERSION !== '2.0') {
+                $warnings[] = array(
+                    'level' => 1,
+                    'message' => 'Only iCalendar version 2.0 as defined in rfc5545 is supported.',
+                    'node' => $this,
+                );
+            }
+        }
+        $version = $this->select('PRODID');
+        if (count($version)!==1) {
+            $warnings[] = array(
+                'level' => 2,
+                'message' => 'The PRODID property must appear in the VCALENDAR component exactly 1 time',
+                'node' => $this,
+            );
+        }
+        if (count($this->CALSCALE) > 1) {
+            $warnings[] = array(
+                'level' => 2,
+                'message' => 'The CALSCALE property must not be specified more than once.',
+                'node' => $this,
+            );
+        }
+        if (count($this->METHOD) > 1) {
+            $warnings[] = array(
+                'level' => 2,
+                'message' => 'The METHOD property must not be specified more than once.',
+                'node' => $this,
+            );
+        }
+
+        $allowedComponents = array(
+            'VEVENT',
+            'VTODO',
+            'VJOURNAL',
+            'VFREEBUSY',
+            'VTIMEZONE',
+        );
+        $allowedProperties = array(
+            'PRODID',
+            'VERSION',
+            'CALSCALE',
+            'METHOD',
+        );
+        $componentsFound = 0;
+        foreach($this->children as $child) {
+            if($child instanceof Component) {
+                $componentsFound++;
+                if (!in_array($child->name, $allowedComponents)) {
+                    $warnings[] = array(
+                        'level' => 1,
+                        'message' => 'The ' . $child->name . " component is not allowed in the VCALENDAR component",
+                        'node' => $this,
+                    );
+                }
+            }
+            if ($child instanceof Property) {
+                if (!in_array($child->name, $allowedProperties)) {
+                    $warnings[] = array(
+                        'level' => 2,
+                        'message' => 'The ' . $child->name . " property is not allowed in the VCALENDAR component",
+                        'node' => $this,
+                    );
+                }
+            }
+        }
+
+        if ($componentsFound===0) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'An iCalendar object must have at least 1 component.',
+                'node' => $this,
+            );
+        }
+
+        return array_merge(
+            $warnings,
+            parent::validate()
+        );
+
+    }
+     */
+
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCard.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCard.php
new file mode 100644
index 0000000..8a50f38
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VCard.php
@@ -0,0 +1,107 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+
+use OldSabre\VObject;
+
+/**
+ * The VCard component
+ *
+ * This component represents the BEGIN:VCARD and END:VCARD found in every
+ * vcard.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VCard extends VObject\Component {
+
+    static $defaultName = 'VCARD';
+
+    /**
+     * VCards with version 2.1, 3.0 and 4.0 are found.
+     *
+     * If the VCARD doesn't know its version, 4.0 is assumed.
+     */
+    const DEFAULT_VERSION = '4.0';
+
+    /**
+     * Validates the node for correctness.
+     *
+     * The following options are supported:
+     *   - Node::REPAIR - If something is broken, and automatic repair may
+     *                    be attempted.
+     *
+     * An array is returned with warnings.
+     *
+     * Every item in the array has the following properties:
+     *    * level - (number between 1 and 3 with severity information)
+     *    * message - (human readable message)
+     *    * node - (reference to the offending node)
+     *
+     * @param int $options
+     * @return array
+     */
+    public function validate($options = 0) {
+
+        $warnings = array();
+
+        $version = $this->select('VERSION');
+        if (count($version)!==1) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'The VERSION property must appear in the VCARD component exactly 1 time',
+                'node' => $this,
+            );
+            if ($options & self::REPAIR) {
+                $this->VERSION = self::DEFAULT_VERSION;
+            }
+        } else {
+            $version = (string)$this->VERSION;
+            if ($version!=='2.1' && $version!=='3.0' && $version!=='4.0') {
+                $warnings[] = array(
+                    'level' => 1,
+                    'message' => 'Only vcard version 4.0 (RFC6350), version 3.0 (RFC2426) or version 2.1 (icm-vcard-2.1) are supported.',
+                    'node' => $this,
+                );
+                if ($options & self::REPAIR) {
+                    $this->VERSION = '4.0';
+                }
+            }
+
+        }
+        $fn = $this->select('FN');
+        if (count($fn)!==1) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'The FN property must appear in the VCARD component exactly 1 time',
+                'node' => $this,
+            );
+            if (($options & self::REPAIR) && count($fn) === 0) {
+                // We're going to try to see if we can use the contents of the
+                // N property.
+                if (isset($this->N)) {
+                    $value = explode(';', (string)$this->N);
+                    if (isset($value[1]) && $value[1]) {
+                        $this->FN = $value[1] . ' ' . $value[0];
+                    } else {
+                        $this->FN = $value[0];
+                    }
+
+                // Otherwise, the ORG property may work
+                } elseif (isset($this->ORG)) {
+                    $this->FN = (string)$this->ORG;
+                }
+
+            }
+        }
+
+        return array_merge(
+            parent::validate($options),
+            $warnings
+        );
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VEvent.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VEvent.php
new file mode 100644
index 0000000..a8af08f
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VEvent.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+use OldSabre\VObject;
+
+/**
+ * VEvent component
+ *
+ * This component contains some additional functionality specific for VEVENT's.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VEvent extends VObject\Component {
+
+    /**
+     * Returns true or false depending on if the event falls in the specified
+     * time-range. This is used for filtering purposes.
+     *
+     * The rules used to determine if an event falls within the specified
+     * time-range is based on the CalDAV specification.
+     *
+     * @param \DateTime $start
+     * @param \DateTime $end
+     * @return bool
+     */
+    public function isInTimeRange(\DateTime $start, \DateTime $end) {
+
+        if ($this->RRULE) {
+            $it = new VObject\RecurrenceIterator($this);
+            $it->fastForward($start);
+
+            // We fast-forwarded to a spot where the end-time of the
+            // recurrence instance exceeded the start of the requested
+            // time-range.
+            //
+            // If the starttime of the recurrence did not exceed the
+            // end of the time range as well, we have a match.
+            return ($it->getDTStart() < $end && $it->getDTEnd() > $start);
+
+        }
+
+        $effectiveStart = $this->DTSTART->getDateTime();
+        if (isset($this->DTEND)) {
+
+            // The DTEND property is considered non inclusive. So for a 3 day
+            // event in july, dtstart and dtend would have to be July 1st and
+            // July 4th respectively.
+            //
+            // See:
+            // http://tools.ietf.org/html/rfc5545#page-54
+            $effectiveEnd = $this->DTEND->getDateTime();
+
+        } elseif (isset($this->DURATION)) {
+            $effectiveEnd = clone $effectiveStart;
+            $effectiveEnd->add( VObject\DateTimeParser::parseDuration($this->DURATION) );
+        } elseif ($this->DTSTART->getDateType() == VObject\Property\DateTime::DATE) {
+            $effectiveEnd = clone $effectiveStart;
+            $effectiveEnd->modify('+1 day');
+        } else {
+            $effectiveEnd = clone $effectiveStart;
+        }
+        return (
+            ($start <= $effectiveEnd) && ($end > $effectiveStart)
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VFreeBusy.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VFreeBusy.php
new file mode 100644
index 0000000..abb622b
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VFreeBusy.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+
+use OldSabre\VObject;
+
+/**
+ * The VFreeBusy component
+ *
+ * This component adds functionality to a component, specific for VFREEBUSY
+ * components.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VFreeBusy extends VObject\Component {
+
+    /**
+     * Checks based on the contained FREEBUSY information, if a timeslot is
+     * available.
+     *
+     * @param DateTime $start
+     * @param Datetime $end
+     * @return bool
+     */
+    public function isFree(\DateTime $start, \Datetime $end) {
+
+        foreach($this->select('FREEBUSY') as $freebusy) {
+
+            // We are only interested in FBTYPE=BUSY (the default),
+            // FBTYPE=BUSY-TENTATIVE or FBTYPE=BUSY-UNAVAILABLE.
+            if (isset($freebusy['FBTYPE']) && strtoupper(substr((string)$freebusy['FBTYPE'],0,4))!=='BUSY') {
+                continue;
+            }
+
+            // The freebusy component can hold more than 1 value, separated by
+            // commas.
+            $periods = explode(',', (string)$freebusy);
+
+            foreach($periods as $period) {
+                // Every period is formatted as [start]/[end]. The start is an
+                // absolute UTC time, the end may be an absolute UTC time, or
+                // duration (relative) value.
+                list($busyStart, $busyEnd) = explode('/', $period);
+
+                $busyStart = VObject\DateTimeParser::parse($busyStart);
+                $busyEnd = VObject\DateTimeParser::parse($busyEnd);
+                if ($busyEnd instanceof \DateInterval) {
+                    $tmp = clone $busyStart;
+                    $tmp->add($busyEnd);
+                    $busyEnd = $tmp;
+                }
+
+                if($start < $busyEnd && $end > $busyStart) {
+                    return false;
+                }
+
+            }
+
+        }
+
+        return true;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VJournal.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VJournal.php
new file mode 100644
index 0000000..25f1593
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VJournal.php
@@ -0,0 +1,46 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+
+use OldSabre\VObject;
+
+/**
+ * VJournal component
+ *
+ * This component contains some additional functionality specific for VJOURNALs.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VJournal extends VObject\Component {
+
+    /**
+     * Returns true or false depending on if the event falls in the specified
+     * time-range. This is used for filtering purposes.
+     *
+     * The rules used to determine if an event falls within the specified
+     * time-range is based on the CalDAV specification.
+     *
+     * @param DateTime $start
+     * @param DateTime $end
+     * @return bool
+     */
+    public function isInTimeRange(\DateTime $start, \DateTime $end) {
+
+        $dtstart = isset($this->DTSTART)?$this->DTSTART->getDateTime():null;
+        if ($dtstart) {
+            $effectiveEnd = clone $dtstart;
+            if ($this->DTSTART->getDateType() == VObject\Property\DateTime::DATE) {
+                $effectiveEnd->modify('+1 day');
+            }
+
+            return ($start <= $effectiveEnd && $end > $dtstart);
+
+        }
+        return false;
+
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VTodo.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VTodo.php
new file mode 100644
index 0000000..c1a3eee
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Component/VTodo.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace OldSabre\VObject\Component;
+
+use OldSabre\VObject;
+
+/**
+ * VTodo component
+ *
+ * This component contains some additional functionality specific for VTODOs.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VTodo extends VObject\Component {
+
+    /**
+     * Returns true or false depending on if the event falls in the specified
+     * time-range. This is used for filtering purposes.
+     *
+     * The rules used to determine if an event falls within the specified
+     * time-range is based on the CalDAV specification.
+     *
+     * @param DateTime $start
+     * @param DateTime $end
+     * @return bool
+     */
+    public function isInTimeRange(\DateTime $start, \DateTime $end) {
+
+        $dtstart = isset($this->DTSTART)?$this->DTSTART->getDateTime():null;
+        $duration = isset($this->DURATION)?VObject\DateTimeParser::parseDuration($this->DURATION):null;
+        $due = isset($this->DUE)?$this->DUE->getDateTime():null;
+        $completed = isset($this->COMPLETED)?$this->COMPLETED->getDateTime():null;
+        $created = isset($this->CREATED)?$this->CREATED->getDateTime():null;
+
+        if ($dtstart) {
+            if ($duration) {
+                $effectiveEnd = clone $dtstart;
+                $effectiveEnd->add($duration);
+                return $start <= $effectiveEnd && $end > $dtstart;
+            } elseif ($due) {
+                return
+                    ($start < $due || $start <= $dtstart) &&
+                    ($end > $dtstart || $end >= $due);
+            } else {
+                return $start <= $dtstart && $end > $dtstart;
+            }
+        }
+        if ($due) {
+            return ($start < $due && $end >= $due);
+        }
+        if ($completed && $created) {
+            return
+                ($start <= $created || $start <= $completed) &&
+                ($end >= $created || $end >= $completed);
+        }
+        if ($completed) {
+            return ($start <= $completed && $end >= $completed);
+        }
+        if ($created) {
+            return ($end > $created);
+        }
+        return true;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/DateTimeParser.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/DateTimeParser.php
new file mode 100644
index 0000000..1b388fa
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/DateTimeParser.php
@@ -0,0 +1,181 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * DateTimeParser
+ *
+ * This class is responsible for parsing the several different date and time
+ * formats iCalendar and vCards have.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class DateTimeParser {
+
+    /**
+     * Parses an iCalendar (rfc5545) formatted datetime and returns a DateTime object
+     *
+     * Specifying a reference timezone is optional. It will only be used
+     * if the non-UTC format is used. The argument is used as a reference, the
+     * returned DateTime object will still be in the UTC timezone.
+     *
+     * @param string $dt
+     * @param DateTimeZone $tz
+     * @return DateTime
+     */
+    static public function parseDateTime($dt,\DateTimeZone $tz = null) {
+
+        // Format is YYYYMMDD + "T" + hhmmss
+        $result = preg_match('/^([1-4][0-9]{3})([0-1][0-9])([0-3][0-9])T([0-2][0-9])([0-5][0-9])([0-5][0-9])([Z]?)$/',$dt,$matches);
+
+        if (!$result) {
+            throw new \LogicException('The supplied iCalendar datetime value is incorrect: ' . $dt);
+        }
+
+        if ($matches[7]==='Z' || is_null($tz)) {
+            $tz = new \DateTimeZone('UTC');
+        }
+        $date = new \DateTime($matches[1] . '-' . $matches[2] . '-' . $matches[3] . ' ' . $matches[4] . ':' . $matches[5] .':' . $matches[6], $tz);
+
+        // Still resetting the timezone, to normalize everything to UTC
+        $date->setTimeZone(new \DateTimeZone('UTC'));
+        return $date;
+
+    }
+
+    /**
+     * Parses an iCalendar (rfc5545) formatted date and returns a DateTime object
+     *
+     * @param string $date
+     * @return DateTime
+     */
+    static public function parseDate($date) {
+
+        // Format is YYYYMMDD
+        $result = preg_match('/^([1-4][0-9]{3})([0-1][0-9])([0-3][0-9])$/',$date,$matches);
+
+        if (!$result) {
+            throw new \LogicException('The supplied iCalendar date value is incorrect: ' . $date);
+        }
+
+        $date = new \DateTime($matches[1] . '-' . $matches[2] . '-' . $matches[3], new \DateTimeZone('UTC'));
+        return $date;
+
+    }
+
+    /**
+     * Parses an iCalendar (RFC5545) formatted duration value.
+     *
+     * This method will either return a DateTimeInterval object, or a string
+     * suitable for strtotime or DateTime::modify.
+     *
+     * @param string $duration
+     * @param bool $asString
+     * @return DateInterval|string
+     */
+    static public function parseDuration($duration, $asString = false) {
+
+        $result = preg_match('/^(?P<plusminus>\+|-)?P((?P<week>\d+)W)?((?P<day>\d+)D)?(T((?P<hour>\d+)H)?((?P<minute>\d+)M)?((?P<second>\d+)S)?)?$/', $duration, $matches);
+        if (!$result) {
+            throw new \LogicException('The supplied iCalendar duration value is incorrect: ' . $duration);
+        }
+
+        if (!$asString) {
+            $invert = false;
+            if ($matches['plusminus']==='-') {
+                $invert = true;
+            }
+
+
+            $parts = array(
+                'week',
+                'day',
+                'hour',
+                'minute',
+                'second',
+            );
+            foreach($parts as $part) {
+                $matches[$part] = isset($matches[$part])&&$matches[$part]?(int)$matches[$part]:0;
+            }
+
+
+            // We need to re-construct the $duration string, because weeks and
+            // days are not supported by DateInterval in the same string.
+            $duration = 'P';
+            $days = $matches['day'];
+            if ($matches['week']) {
+                $days+=$matches['week']*7;
+            }
+            if ($days)
+                $duration.=$days . 'D';
+
+            if ($matches['minute'] || $matches['second'] || $matches['hour']) {
+                $duration.='T';
+
+                if ($matches['hour'])
+                    $duration.=$matches['hour'].'H';
+
+                if ($matches['minute'])
+                    $duration.=$matches['minute'].'M';
+
+                if ($matches['second'])
+                    $duration.=$matches['second'].'S';
+
+            }
+
+            if ($duration==='P') {
+                $duration = 'PT0S';
+            }
+            $iv = new \DateInterval($duration);
+            if ($invert) $iv->invert = true;
+
+            return $iv;
+
+        }
+
+
+
+        $parts = array(
+            'week',
+            'day',
+            'hour',
+            'minute',
+            'second',
+        );
+
+        $newDur = '';
+        foreach($parts as $part) {
+            if (isset($matches[$part]) && $matches[$part]) {
+                $newDur.=' '.$matches[$part] . ' ' . $part . 's';
+            }
+        }
+
+        $newDur = ($matches['plusminus']==='-'?'-':'+') . trim($newDur);
+        if ($newDur === '+') { $newDur = '+0 seconds'; };
+        return $newDur;
+
+    }
+
+    /**
+     * Parses either a Date or DateTime, or Duration value.
+     *
+     * @param string $date
+     * @param DateTimeZone|string $referenceTZ
+     * @return DateTime|DateInterval
+     */
+    static public function parse($date, $referenceTZ = null) {
+
+        if ($date[0]==='P' || ($date[0]==='-' && $date[1]==='P')) {
+            return self::parseDuration($date);
+        } elseif (strlen($date)===8) {
+            return self::parseDate($date);
+        } else {
+            return self::parseDateTime($date, $referenceTZ);
+        }
+
+    }
+
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Document.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Document.php
new file mode 100644
index 0000000..b29d971
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Document.php
@@ -0,0 +1,109 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * Document
+ *
+ * A document is just like a component, except that it's also the top level
+ * element.
+ *
+ * Both a VCALENDAR and a VCARD are considered documents.
+ *
+ * This class also provides a registry for document types.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH. All rights reserved.
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+abstract class Document extends Component {
+
+    /**
+     * The default name for this component.
+     *
+     * This should be 'VCALENDAR' or 'VCARD'.
+     *
+     * @var string
+     */
+    static $defaultName;
+
+    /**
+     * Creates a new document.
+     *
+     * We're changing the default behavior slightly here. First, we don't want
+     * to have to specify a name (we already know it), and we want to allow
+     * children to be specified in the first argument.
+     *
+     * But, the default behavior also works.
+     *
+     * So the two sigs:
+     *
+     * new Document(array $children = array());
+     * new Document(string $name, array $children = array())
+     *
+     * @return void
+     */
+    public function __construct() {
+
+        $args = func_get_args();
+        if (count($args)===0 || is_array($args[0])) {
+            array_unshift($args, static::$defaultName);
+            call_user_func_array(array('parent', '__construct'), $args);
+        } else {
+            call_user_func_array(array('parent', '__construct'), $args);
+        }
+
+    }
+
+    /**
+     * Creates a new component
+     *
+     * This method automatically searches for the correct component class, based
+     * on its name.
+     *
+     * You can specify the children either in key=>value syntax, in which case
+     * properties will automatically be created, or you can just pass a list of
+     * Component and Property object.
+     *
+     * @param string $name
+     * @param array $children
+     * @return Component
+     */
+    public function createComponent($name, array $children = array()) {
+
+        $component = Component::create($name);
+        foreach($children as $k=>$v) {
+
+            if ($v instanceof Node) {
+                $component->add($v);
+            } else {
+                $component->add($k, $v);
+            }
+
+        }
+        return $component;
+
+    }
+
+    /**
+     * Factory method for creating new properties
+     *
+     * This method automatically searches for the correct property class, based
+     * on its name.
+     *
+     * You can specify the parameters either in key=>value syntax, in which case
+     * parameters will automatically be created, or you can just pass a list of
+     * Parameter objects.
+     *
+     * @param string $name
+     * @param mixed $value
+     * @param array $parameters
+     * @return Property
+     */
+    public function createProperty($name, $value = null, array $parameters = array()) {
+
+        return Property::create($name, $value, $parameters);
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ElementList.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ElementList.php
new file mode 100644
index 0000000..317d784
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ElementList.php
@@ -0,0 +1,172 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * VObject ElementList
+ *
+ * This class represents a list of elements. Lists are the result of queries,
+ * such as doing $vcalendar->vevent where there's multiple VEVENT objects.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class ElementList implements \Iterator, \Countable, \ArrayAccess {
+
+    /**
+     * Inner elements
+     *
+     * @var array
+     */
+    protected $elements = array();
+
+    /**
+     * Creates the element list.
+     *
+     * @param array $elements
+     */
+    public function __construct(array $elements) {
+
+        $this->elements = $elements;
+
+    }
+
+    /* {{{ Iterator interface */
+
+    /**
+     * Current position
+     *
+     * @var int
+     */
+    private $key = 0;
+
+    /**
+     * Returns current item in iteration
+     *
+     * @return Element
+     */
+    public function current() {
+
+        return $this->elements[$this->key];
+
+    }
+
+    /**
+     * To the next item in the iterator
+     *
+     * @return void
+     */
+    public function next() {
+
+        $this->key++;
+
+    }
+
+    /**
+     * Returns the current iterator key
+     *
+     * @return int
+     */
+    public function key() {
+
+        return $this->key;
+
+    }
+
+    /**
+     * Returns true if the current position in the iterator is a valid one
+     *
+     * @return bool
+     */
+    public function valid() {
+
+        return isset($this->elements[$this->key]);
+
+    }
+
+    /**
+     * Rewinds the iterator
+     *
+     * @return void
+     */
+    public function rewind() {
+
+        $this->key = 0;
+
+    }
+
+    /* }}} */
+
+    /* {{{ Countable interface */
+
+    /**
+     * Returns the number of elements
+     *
+     * @return int
+     */
+    public function count() {
+
+        return count($this->elements);
+
+    }
+
+    /* }}} */
+
+    /* {{{ ArrayAccess Interface */
+
+
+    /**
+     * Checks if an item exists through ArrayAccess.
+     *
+     * @param int $offset
+     * @return bool
+     */
+    public function offsetExists($offset) {
+
+        return isset($this->elements[$offset]);
+
+    }
+
+    /**
+     * Gets an item through ArrayAccess.
+     *
+     * @param int $offset
+     * @return mixed
+     */
+    public function offsetGet($offset) {
+
+        return $this->elements[$offset];
+
+    }
+
+    /**
+     * Sets an item through ArrayAccess.
+     *
+     * @param int $offset
+     * @param mixed $value
+     * @return void
+     */
+    public function offsetSet($offset,$value) {
+
+        throw new \LogicException('You can not add new objects to an ElementList');
+
+    }
+
+    /**
+     * Sets an item through ArrayAccess.
+     *
+     * This method just forwards the request to the inner iterator
+     *
+     * @param int $offset
+     * @return void
+     */
+    public function offsetUnset($offset) {
+
+        throw new \LogicException('You can not remove objects from an ElementList');
+
+    }
+
+    /* }}} */
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/FreeBusyGenerator.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/FreeBusyGenerator.php
new file mode 100644
index 0000000..a7a8ef3
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/FreeBusyGenerator.php
@@ -0,0 +1,322 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * This class helps with generating FREEBUSY reports based on existing sets of
+ * objects.
+ *
+ * It only looks at VEVENT and VFREEBUSY objects from the sourcedata, and
+ * generates a single VFREEBUSY object.
+ *
+ * VFREEBUSY components are described in RFC5545, The rules for what should
+ * go in a single freebusy report is taken from RFC4791, section 7.10.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class FreeBusyGenerator {
+
+    /**
+     * Input objects
+     *
+     * @var array
+     */
+    protected $objects;
+
+    /**
+     * Start of range
+     *
+     * @var DateTime|null
+     */
+    protected $start;
+
+    /**
+     * End of range
+     *
+     * @var DateTime|null
+     */
+    protected $end;
+
+    /**
+     * VCALENDAR object
+     *
+     * @var Component
+     */
+    protected $baseObject;
+
+    /**
+     * Creates the generator.
+     *
+     * Check the setTimeRange and setObjects methods for details about the
+     * arguments.
+     *
+     * @param DateTime $start
+     * @param DateTime $end
+     * @param mixed $objects
+     * @return void
+     */
+    public function __construct(\DateTime $start = null, \DateTime $end = null, $objects = null) {
+
+        if ($start && $end) {
+            $this->setTimeRange($start, $end);
+        }
+
+        if ($objects) {
+            $this->setObjects($objects);
+        }
+
+    }
+
+    /**
+     * Sets the VCALENDAR object.
+     *
+     * If this is set, it will not be generated for you. You are responsible
+     * for setting things like the METHOD, CALSCALE, VERSION, etc..
+     *
+     * The VFREEBUSY object will be automatically added though.
+     *
+     * @param Component $vcalendar
+     * @return void
+     */
+    public function setBaseObject(Component $vcalendar) {
+
+        $this->baseObject = $vcalendar;
+
+    }
+
+    /**
+     * Sets the input objects
+     *
+     * You must either specify a valendar object as a strong, or as the parse
+     * Component.
+     * It's also possible to specify multiple objects as an array.
+     *
+     * @param mixed $objects
+     * @return void
+     */
+    public function setObjects($objects) {
+
+        if (!is_array($objects)) {
+            $objects = array($objects);
+        }
+
+        $this->objects = array();
+        foreach($objects as $object) {
+
+            if (is_string($object)) {
+                $this->objects[] = Reader::read($object);
+            } elseif ($object instanceof Component) {
+                $this->objects[] = $object;
+            } else {
+                throw new \InvalidArgumentException('You can only pass strings or \\OldSabre\\VObject\\Component arguments to setObjects');
+            }
+
+        }
+
+    }
+
+    /**
+     * Sets the time range
+     *
+     * Any freebusy object falling outside of this time range will be ignored.
+     *
+     * @param DateTime $start
+     * @param DateTime $end
+     * @return void
+     */
+    public function setTimeRange(\DateTime $start = null, \DateTime $end = null) {
+
+        $this->start = $start;
+        $this->end = $end;
+
+    }
+
+    /**
+     * Parses the input data and returns a correct VFREEBUSY object, wrapped in
+     * a VCALENDAR.
+     *
+     * @return Component
+     */
+    public function getResult() {
+
+        $busyTimes = array();
+
+        foreach($this->objects as $object) {
+
+            foreach($object->getBaseComponents() as $component) {
+
+                switch($component->name) {
+
+                    case 'VEVENT' :
+
+                        $FBTYPE = 'BUSY';
+                        if (isset($component->TRANSP) && (strtoupper($component->TRANSP) === 'TRANSPARENT')) {
+                            break;
+                        }
+                        if (isset($component->STATUS)) {
+                            $status = strtoupper($component->STATUS);
+                            if ($status==='CANCELLED') {
+                                break;
+                            }
+                            if ($status==='TENTATIVE') {
+                                $FBTYPE = 'BUSY-TENTATIVE';
+                            }
+                        }
+
+                        $times = array();
+
+                        if ($component->RRULE) {
+
+                            $iterator = new RecurrenceIterator($object, (string)$component->uid);
+                            if ($this->start) {
+                                $iterator->fastForward($this->start);
+                            }
+
+                            $maxRecurrences = 200;
+
+                            while($iterator->valid() && --$maxRecurrences) {
+
+                                $startTime = $iterator->getDTStart();
+                                if ($this->end && $startTime > $this->end) {
+                                    break;
+                                }
+                                $times[] = array(
+                                    $iterator->getDTStart(),
+                                    $iterator->getDTEnd(),
+                                );
+
+                                $iterator->next();
+
+                            }
+
+                        } else {
+
+                            $startTime = $component->DTSTART->getDateTime();
+                            if ($this->end && $startTime > $this->end) {
+                                break;
+                            }
+                            $endTime = null;
+                            if (isset($component->DTEND)) {
+                                $endTime = $component->DTEND->getDateTime();
+                            } elseif (isset($component->DURATION)) {
+                                $duration = DateTimeParser::parseDuration((string)$component->DURATION);
+                                $endTime = clone $startTime;
+                                $endTime->add($duration);
+                            } elseif ($component->DTSTART->getDateType() === Property\DateTime::DATE) {
+                                $endTime = clone $startTime;
+                                $endTime->modify('+1 day');
+                            } else {
+                                // The event had no duration (0 seconds)
+                                break;
+                            }
+
+                            $times[] = array($startTime, $endTime);
+
+                        }
+
+                        foreach($times as $time) {
+
+                            if ($this->end && $time[0] > $this->end) break;
+                            if ($this->start && $time[1] < $this->start) break;
+
+                            $busyTimes[] = array(
+                                $time[0],
+                                $time[1],
+                                $FBTYPE,
+                            );
+                        }
+                        break;
+
+                    case 'VFREEBUSY' :
+                        foreach($component->FREEBUSY as $freebusy) {
+
+                            $fbType = isset($freebusy['FBTYPE'])?strtoupper($freebusy['FBTYPE']):'BUSY';
+
+                            // Skipping intervals marked as 'free'
+                            if ($fbType==='FREE')
+                                continue;
+
+                            $values = explode(',', $freebusy);
+                            foreach($values as $value) {
+                                list($startTime, $endTime) = explode('/', $value);
+                                $startTime = DateTimeParser::parseDateTime($startTime);
+
+                                if (substr($endTime,0,1)==='P' || substr($endTime,0,2)==='-P') {
+                                    $duration = DateTimeParser::parseDuration($endTime);
+                                    $endTime = clone $startTime;
+                                    $endTime->add($duration);
+                                } else {
+                                    $endTime = DateTimeParser::parseDateTime($endTime);
+                                }
+
+                                if($this->start && $this->start > $endTime) continue;
+                                if($this->end && $this->end < $startTime) continue;
+                                $busyTimes[] = array(
+                                    $startTime,
+                                    $endTime,
+                                    $fbType
+                                );
+
+                            }
+
+
+                        }
+                        break;
+
+
+
+                }
+
+
+            }
+
+        }
+
+        if ($this->baseObject) {
+            $calendar = $this->baseObject;
+        } else {
+            $calendar = Component::create('VCALENDAR');
+            $calendar->version = '2.0';
+            $calendar->prodid = '-//Sabre//Sabre VObject ' . Version::VERSION . '//EN';
+            $calendar->calscale = 'GREGORIAN';
+        }
+
+        $vfreebusy = Component::create('VFREEBUSY');
+        $calendar->add($vfreebusy);
+
+        if ($this->start) {
+            $dtstart = Property::create('DTSTART');
+            $dtstart->setDateTime($this->start,Property\DateTime::UTC);
+            $vfreebusy->add($dtstart);
+        }
+        if ($this->end) {
+            $dtend = Property::create('DTEND');
+            $dtend->setDateTime($this->end,Property\DateTime::UTC);
+            $vfreebusy->add($dtend);
+        }
+        $dtstamp = Property::create('DTSTAMP');
+        $dtstamp->setDateTime(new \DateTime('now'), Property\DateTime::UTC);
+        $vfreebusy->add($dtstamp);
+
+        foreach($busyTimes as $busyTime) {
+
+            $busyTime[0]->setTimeZone(new \DateTimeZone('UTC'));
+            $busyTime[1]->setTimeZone(new \DateTimeZone('UTC'));
+
+            $prop = Property::create(
+                'FREEBUSY',
+                $busyTime[0]->format('Ymd\\THis\\Z') . '/' . $busyTime[1]->format('Ymd\\THis\\Z')
+            );
+            $prop['FBTYPE'] = $busyTime[2];
+            $vfreebusy->add($prop);
+
+        }
+
+        return $calendar;
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Node.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Node.php
new file mode 100644
index 0000000..b9e265b
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Node.php
@@ -0,0 +1,187 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * Base class for all nodes
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+abstract class Node implements \IteratorAggregate, \ArrayAccess, \Countable {
+
+    /**
+     * The following constants are used by the validate() method.
+     */
+    const REPAIR = 1;
+
+    /**
+     * Turns the object back into a serialized blob.
+     *
+     * @return string
+     */
+    abstract function serialize();
+
+    /**
+     * Iterator override
+     *
+     * @var ElementList
+     */
+    protected $iterator = null;
+
+    /**
+     * A link to the parent node
+     *
+     * @var Node
+     */
+    public $parent = null;
+
+    /**
+     * Validates the node for correctness.
+     *
+     * The following options are supported:
+     *   - Node::REPAIR - If something is broken, and automatic repair may
+     *                    be attempted.
+     *
+     * An array is returned with warnings.
+     *
+     * Every item in the array has the following properties:
+     *    * level - (number between 1 and 3 with severity information)
+     *    * message - (human readable message)
+     *    * node - (reference to the offending node)
+     *
+     * @param int $options
+     * @return array
+     */
+    public function validate($options = 0) {
+
+        return array();
+
+    }
+
+    /* {{{ IteratorAggregator interface */
+
+    /**
+     * Returns the iterator for this object
+     *
+     * @return ElementList
+     */
+    public function getIterator() {
+
+        if (!is_null($this->iterator))
+            return $this->iterator;
+
+        return new ElementList(array($this));
+
+    }
+
+    /**
+     * Sets the overridden iterator
+     *
+     * Note that this is not actually part of the iterator interface
+     *
+     * @param ElementList $iterator
+     * @return void
+     */
+    public function setIterator(ElementList $iterator) {
+
+        $this->iterator = $iterator;
+
+    }
+
+    /* }}} */
+
+    /* {{{ Countable interface */
+
+    /**
+     * Returns the number of elements
+     *
+     * @return int
+     */
+    public function count() {
+
+        $it = $this->getIterator();
+        return $it->count();
+
+    }
+
+    /* }}} */
+
+    /* {{{ ArrayAccess Interface */
+
+
+    /**
+     * Checks if an item exists through ArrayAccess.
+     *
+     * This method just forwards the request to the inner iterator
+     *
+     * @param int $offset
+     * @return bool
+     */
+    public function offsetExists($offset) {
+
+        $iterator = $this->getIterator();
+        return $iterator->offsetExists($offset);
+
+    }
+
+    /**
+     * Gets an item through ArrayAccess.
+     *
+     * This method just forwards the request to the inner iterator
+     *
+     * @param int $offset
+     * @return mixed
+     */
+    public function offsetGet($offset) {
+
+        $iterator = $this->getIterator();
+        return $iterator->offsetGet($offset);
+
+    }
+
+    /**
+     * Sets an item through ArrayAccess.
+     *
+     * This method just forwards the request to the inner iterator
+     *
+     * @param int $offset
+     * @param mixed $value
+     * @return void
+     */
+    public function offsetSet($offset,$value) {
+
+        $iterator = $this->getIterator();
+        $iterator->offsetSet($offset,$value);
+
+    // @codeCoverageIgnoreStart
+    //
+    // This method always throws an exception, so we ignore the closing
+    // brace
+    }
+    // @codeCoverageIgnoreEnd
+
+    /**
+     * Sets an item through ArrayAccess.
+     *
+     * This method just forwards the request to the inner iterator
+     *
+     * @param int $offset
+     * @return void
+     */
+    public function offsetUnset($offset) {
+
+        $iterator = $this->getIterator();
+        $iterator->offsetUnset($offset);
+
+    // @codeCoverageIgnoreStart
+    //
+    // This method always throws an exception, so we ignore the closing
+    // brace
+    }
+    // @codeCoverageIgnoreEnd
+
+    /* }}} */
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Parameter.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Parameter.php
new file mode 100644
index 0000000..43d2433
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Parameter.php
@@ -0,0 +1,100 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * VObject Parameter
+ *
+ * This class represents a parameter. A parameter is always tied to a property.
+ * In the case of:
+ *   DTSTART;VALUE=DATE:20101108
+ * VALUE=DATE would be the parameter name and value.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Parameter extends Node {
+
+    /**
+     * Parameter name
+     *
+     * @var string
+     */
+    public $name;
+
+    /**
+     * Parameter value
+     *
+     * @var string
+     */
+    public $value;
+
+    /**
+     * Sets up the object
+     *
+     * @param string $name
+     * @param string $value
+     */
+    public function __construct($name, $value = null) {
+
+        if (!is_scalar($value) && !is_null($value)) {
+            throw new \InvalidArgumentException('The value argument must be a scalar value or null');
+        }
+
+        $this->name = strtoupper($name);
+        $this->value = $value;
+
+    }
+
+    /**
+     * Returns the parameter's internal value.
+     *
+     * @return string
+     */
+    public function getValue() {
+
+        return $this->value;
+
+    }
+
+
+    /**
+     * Turns the object back into a serialized blob.
+     *
+     * @return string
+     */
+    public function serialize() {
+
+        if (is_null($this->value)) {
+            return $this->name;
+        }
+        $src = array(
+            '\\',
+            "\n",
+            ';',
+            ',',
+        );
+        $out = array(
+            '\\\\',
+            '\n',
+            '\;',
+            '\,',
+        );
+
+        return $this->name . '=' . str_replace($src, $out, $this->value);
+
+    }
+
+    /**
+     * Called when this object is being cast to a string
+     *
+     * @return string
+     */
+    public function __toString() {
+
+        return $this->value;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ParseException.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ParseException.php
new file mode 100644
index 0000000..8e24d78
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/ParseException.php
@@ -0,0 +1,12 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * Exception thrown by Reader if an invalid object was attempted to be parsed.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class ParseException extends \Exception { }
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property.php
new file mode 100644
index 0000000..ad99f59
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property.php
@@ -0,0 +1,442 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * VObject Property
+ *
+ * A property in VObject is usually in the form PARAMNAME:paramValue.
+ * An example is : SUMMARY:Weekly meeting
+ *
+ * Properties can also have parameters:
+ * SUMMARY;LANG=en:Weekly meeting.
+ *
+ * Parameters can be accessed using the ArrayAccess interface.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Property extends Node {
+
+    /**
+     * Propertyname
+     *
+     * @var string
+     */
+    public $name;
+
+    /**
+     * Group name
+     *
+     * This may be something like 'HOME' for vcards.
+     *
+     * @var string
+     */
+    public $group;
+
+    /**
+     * Property parameters
+     *
+     * @var array
+     */
+    public $parameters = array();
+
+    /**
+     * Property value
+     *
+     * @var string
+     */
+    public $value;
+
+    /**
+     * If properties are added to this map, they will be automatically mapped
+     * to their respective classes, if parsed by the reader or constructed with
+     * the 'create' method.
+     *
+     * @var array
+     */
+    static public $classMap = array(
+        'COMPLETED'     => 'OldSabre\\VObject\\Property\\DateTime',
+        'CREATED'       => 'OldSabre\\VObject\\Property\\DateTime',
+        'DTEND'         => 'OldSabre\\VObject\\Property\\DateTime',
+        'DTSTAMP'       => 'OldSabre\\VObject\\Property\\DateTime',
+        'DTSTART'       => 'OldSabre\\VObject\\Property\\DateTime',
+        'DUE'           => 'OldSabre\\VObject\\Property\\DateTime',
+        'EXDATE'        => 'OldSabre\\VObject\\Property\\MultiDateTime',
+        'LAST-MODIFIED' => 'OldSabre\\VObject\\Property\\DateTime',
+        'RECURRENCE-ID' => 'OldSabre\\VObject\\Property\\DateTime',
+        'TRIGGER'       => 'OldSabre\\VObject\\Property\\DateTime',
+        'N'             => 'OldSabre\\VObject\\Property\\Compound',
+        'ORG'           => 'OldSabre\\VObject\\Property\\Compound',
+        'ADR'           => 'OldSabre\\VObject\\Property\\Compound',
+        'CATEGORIES'    => 'OldSabre\\VObject\\Property\\Compound',
+    );
+
+    /**
+     * Creates the new property by name, but in addition will also see if
+     * there's a class mapped to the property name.
+     *
+     * Parameters can be specified with the optional third argument. Parameters
+     * must be a key->value map of the parameter name, and value. If the value
+     * is specified as an array, it is assumed that multiple parameters with
+     * the same name should be added.
+     *
+     * @param string $name
+     * @param string $value
+     * @param array $parameters
+     * @return Property
+     */
+    static public function create($name, $value = null, array $parameters = array()) {
+
+        $name = strtoupper($name);
+        $shortName = $name;
+        $group = null;
+        if (strpos($shortName,'.')!==false) {
+            list($group, $shortName) = explode('.', $shortName);
+        }
+
+        if (isset(self::$classMap[$shortName])) {
+            return new self::$classMap[$shortName]($name, $value, $parameters);
+        } else {
+            return new self($name, $value, $parameters);
+        }
+
+    }
+
+    /**
+     * Creates a new property object
+     *
+     * Parameters can be specified with the optional third argument. Parameters
+     * must be a key->value map of the parameter name, and value. If the value
+     * is specified as an array, it is assumed that multiple parameters with
+     * the same name should be added.
+     *
+     * @param string $name
+     * @param string $value
+     * @param array $parameters
+     */
+    public function __construct($name, $value = null, array $parameters = array()) {
+
+        if (!is_scalar($value) && !is_null($value)) {
+            throw new \InvalidArgumentException('The value argument must be scalar or null');
+        }
+
+        $name = strtoupper($name);
+        $group = null;
+        if (strpos($name,'.')!==false) {
+            list($group, $name) = explode('.', $name);
+        }
+        $this->name = $name;
+        $this->group = $group;
+        $this->setValue($value);
+
+        foreach($parameters as $paramName => $paramValues) {
+
+            if (!is_array($paramValues)) {
+                $paramValues = array($paramValues);
+            }
+
+            foreach($paramValues as $paramValue) {
+                $this->add($paramName, $paramValue);
+            }
+
+        }
+
+    }
+
+    /**
+     * Updates the internal value
+     *
+     * @param string $value
+     * @return void
+     */
+    public function setValue($value) {
+
+        $this->value = $value;
+
+    }
+
+    /**
+     * Returns the internal value
+     *
+     * @param string $value
+     * @return string
+     */
+    public function getValue() {
+
+        return $this->value;
+
+    }
+
+    /**
+     * Turns the object back into a serialized blob.
+     *
+     * @return string
+     */
+    public function serialize() {
+
+        $str = $this->name;
+        if ($this->group) $str = $this->group . '.' . $this->name;
+
+        foreach($this->parameters as $param) {
+
+            $str.=';' . $param->serialize();
+
+        }
+
+        $src = array(
+            '\\',
+            "\n",
+        );
+        $out = array(
+            '\\\\',
+            '\n',
+        );
+        $str.=':' . str_replace($src, $out, $this->value);
+
+        $out = '';
+        while(strlen($str)>0) {
+            if (strlen($str)>75) {
+                $out.= mb_strcut($str,0,75,'utf-8') . "\r\n";
+                $str = ' ' . mb_strcut($str,75,strlen($str),'utf-8');
+            } else {
+                $out.=$str . "\r\n";
+                $str='';
+                break;
+            }
+        }
+
+        return $out;
+
+    }
+
+    /**
+     * Adds a new componenten or element
+     *
+     * You can call this method with the following syntaxes:
+     *
+     * add(Parameter $element)
+     * add(string $name, $value)
+     *
+     * The first version adds an Parameter
+     * The second adds a property as a string.
+     *
+     * @param mixed $item
+     * @param mixed $itemValue
+     * @return void
+     */
+    public function add($item, $itemValue = null) {
+
+        if ($item instanceof Parameter) {
+            if (!is_null($itemValue)) {
+                throw new \InvalidArgumentException('The second argument must not be specified, when passing a VObject');
+            }
+            $item->parent = $this;
+            $this->parameters[] = $item;
+        } elseif(is_string($item)) {
+
+            $parameter = new Parameter($item,$itemValue);
+            $parameter->parent = $this;
+            $this->parameters[] = $parameter;
+
+        } else {
+
+            throw new \InvalidArgumentException('The first argument must either be a Node a string');
+
+        }
+
+    }
+
+    /* ArrayAccess interface {{{ */
+
+    /**
+     * Checks if an array element exists
+     *
+     * @param mixed $name
+     * @return bool
+     */
+    public function offsetExists($name) {
+
+        if (is_int($name)) return parent::offsetExists($name);
+
+        $name = strtoupper($name);
+
+        foreach($this->parameters as $parameter) {
+            if ($parameter->name == $name) return true;
+        }
+        return false;
+
+    }
+
+    /**
+     * Returns a parameter, or parameter list.
+     *
+     * @param string $name
+     * @return Node
+     */
+    public function offsetGet($name) {
+
+        if (is_int($name)) return parent::offsetGet($name);
+        $name = strtoupper($name);
+
+        $result = array();
+        foreach($this->parameters as $parameter) {
+            if ($parameter->name == $name)
+                $result[] = $parameter;
+        }
+
+        if (count($result)===0) {
+            return null;
+        } elseif (count($result)===1) {
+            return $result[0];
+        } else {
+            $result[0]->setIterator(new ElementList($result));
+            return $result[0];
+        }
+
+    }
+
+    /**
+     * Creates a new parameter
+     *
+     * @param string $name
+     * @param mixed $value
+     * @return void
+     */
+    public function offsetSet($name, $value) {
+
+        if (is_int($name)) parent::offsetSet($name, $value);
+
+        if (is_scalar($value)) {
+            if (!is_string($name))
+                throw new \InvalidArgumentException('A parameter name must be specified. This means you cannot use the $array[]="string" to add parameters.');
+
+            $this->offsetUnset($name);
+            $parameter = new Parameter($name, $value);
+            $parameter->parent = $this;
+            $this->parameters[] = $parameter;
+
+        } elseif ($value instanceof Parameter) {
+            if (!is_null($name))
+                throw new \InvalidArgumentException('Don\'t specify a parameter name if you\'re passing a \\OldSabre\\VObject\\Parameter. Add using $array[]=$parameterObject.');
+
+            $value->parent = $this;
+            $this->parameters[] = $value;
+        } else {
+            throw new \InvalidArgumentException('You can only add parameters to the property object');
+        }
+
+    }
+
+    /**
+     * Removes one or more parameters with the specified name
+     *
+     * @param string $name
+     * @return void
+     */
+    public function offsetUnset($name) {
+
+        if (is_int($name)) parent::offsetUnset($name);
+        $name = strtoupper($name);
+
+        foreach($this->parameters as $key=>$parameter) {
+            if ($parameter->name == $name) {
+                $parameter->parent = null;
+                unset($this->parameters[$key]);
+            }
+
+        }
+
+    }
+
+    /* }}} */
+
+    /**
+     * Called when this object is being cast to a string
+     *
+     * @return string
+     */
+    public function __toString() {
+
+        return (string)$this->value;
+
+    }
+
+    /**
+     * This method is automatically called when the object is cloned.
+     * Specifically, this will ensure all child elements are also cloned.
+     *
+     * @return void
+     */
+    public function __clone() {
+
+        foreach($this->parameters as $key=>$child) {
+            $this->parameters[$key] = clone $child;
+            $this->parameters[$key]->parent = $this;
+        }
+
+    }
+
+    /**
+     * Validates the node for correctness.
+     *
+     * The following options are supported:
+     *   - Node::REPAIR - If something is broken, and automatic repair may
+     *                    be attempted.
+     *
+     * An array is returned with warnings.
+     *
+     * Every item in the array has the following properties:
+     *    * level - (number between 1 and 3 with severity information)
+     *    * message - (human readable message)
+     *    * node - (reference to the offending node)
+     *
+     * @param int $options
+     * @return array
+     */
+    public function validate($options = 0) {
+
+        $warnings = array();
+
+        // Checking if our value is UTF-8
+        if (!StringUtil::isUTF8($this->value)) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'Property is not valid UTF-8!',
+                'node' => $this,
+            );
+            if ($options & self::REPAIR) {
+                $this->value = StringUtil::convertToUTF8($this->value);
+            }
+        }
+
+        // Checking if the propertyname does not contain any invalid bytes.
+        if (!preg_match('/^([A-Z0-9-]+)$/', $this->name)) {
+            $warnings[] = array(
+                'level' => 1,
+                'message' => 'The propertyname: ' . $this->name . ' contains invalid characters. Only A-Z, 0-9 and - are allowed',
+                'node' => $this,
+            );
+            if ($options & self::REPAIR) {
+                // Uppercasing and converting underscores to dashes.
+                $this->name = strtoupper(
+                    str_replace('_', '-', $this->name)
+                );
+                // Removing every other invalid character
+                $this->name = preg_replace('/([^A-Z0-9-])/u', '', $this->name);
+
+            }
+
+        }
+
+        // Validating inner parameters
+        foreach($this->parameters as $param) {
+            $warnings = array_merge($warnings, $param->validate($options));
+        }
+
+        return $warnings;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/Compound.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/Compound.php
new file mode 100644
index 0000000..e46946e
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/Compound.php
@@ -0,0 +1,125 @@
+<?php
+
+namespace OldSabre\VObject\Property;
+
+use OldSabre\VObject;
+
+/**
+ * Compound property.
+ *
+ * This class adds (de)serialization of compound properties to/from arrays.
+ *
+ * Currently the following properties from RFC 6350 are mapped to use this
+ * class:
+ *
+ *  N:          Section 6.2.2
+ *  ADR:        Section 6.3.1
+ *  ORG:        Section 6.6.4
+ *  CATEGORIES: Section 6.7.1
+ *
+ * In order to use this correctly, you must call setParts and getParts to
+ * retrieve and modify dates respectively.
+ *
+ * @author Thomas Tanghus (http://tanghus.net/)
+ * @author Lars Kneschke
+ * @author Evert Pot (http://evertpot.com/)
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Compound extends VObject\Property {
+
+    /**
+     * If property names are added to this map, they will be (de)serialised as arrays
+     * using the getParts() and setParts() methods.
+     * The keys are the property names, values are delimiter chars.
+     *
+     * @var array
+     */
+    static public $delimiterMap = array(
+        'N'           =>    ';',
+        'ADR'         =>    ';',
+        'ORG'         =>    ';',
+        'CATEGORIES'  =>    ',',
+    );
+
+    /**
+     * The currently used delimiter.
+     *
+     * @var string
+     */
+    protected $delimiter = null;
+
+    /**
+     * Get a compound value as an array.
+     *
+     * @param $name string
+     * @return array
+     */
+    public function getParts() {
+
+        if (is_null($this->value)) {
+            return array();
+        }
+
+        $delimiter = $this->getDelimiter();
+
+        // split by any $delimiter which is NOT prefixed by a slash.
+        // Note that this is not a a perfect solution. If a value is prefixed
+        // by two slashes, it should actually be split anyway.
+        //
+        // Hopefully we can fix this better in a future version, where we can
+        // break compatibility a bit.
+        $compoundValues = preg_split("/(?<!\\\)$delimiter/", $this->value);
+
+        // remove slashes from any semicolon and comma left escaped in the single values
+        $compoundValues = array_map(
+            function($val) {
+                return strtr($val, array('\,' => ',', '\;' => ';'));
+        }, $compoundValues);
+
+        return $compoundValues;
+
+    }
+
+    /**
+     * Returns the delimiter for this property.
+     *
+     * @return string
+     */
+    public function getDelimiter() {
+
+        if (!$this->delimiter) {
+            if (isset(self::$delimiterMap[$this->name])) {
+                $this->delimiter = self::$delimiterMap[$this->name];
+            } else {
+                // To be a bit future proof, we are going to default the
+                // delimiter to ;
+                $this->delimiter = ';';
+            }
+        }
+        return $this->delimiter;
+
+    }
+
+    /**
+     * Set a compound value as an array.
+     *
+     *
+     * @param $name string
+     * @return array
+     */
+    public function setParts(array $values) {
+
+        // add slashes to all semicolons and commas in the single values
+        $values = array_map(
+            function($val) {
+                return strtr($val, array(',' => '\,', ';' => '\;'));
+            }, $values);
+
+        $this->setValue(
+            implode($this->getDelimiter(), $values)
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/DateTime.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/DateTime.php
new file mode 100644
index 0000000..36299c9
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/DateTime.php
@@ -0,0 +1,245 @@
+<?php
+
+namespace OldSabre\VObject\Property;
+
+use OldSabre\VObject;
+
+/**
+ * DateTime property
+ *
+ * This element is used for iCalendar properties such as the DTSTART property.
+ * It basically provides a few helper functions that make it easier to deal
+ * with these. It supports both DATE-TIME and DATE values.
+ *
+ * In order to use this correctly, you must call setDateTime and getDateTime to
+ * retrieve and modify dates respectively.
+ *
+ * If you use the 'value' or properties directly, this object does not keep
+ * reference and results might appear incorrectly.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class DateTime extends VObject\Property {
+
+    /**
+     * Local 'floating' time
+     */
+    const LOCAL = 1;
+
+    /**
+     * UTC-based time
+     */
+    const UTC = 2;
+
+    /**
+     * Local time plus timezone
+     */
+    const LOCALTZ = 3;
+
+    /**
+     * Only a date, time is ignored
+     */
+    const DATE = 4;
+
+    /**
+     * DateTime representation
+     *
+     * @var \DateTime
+     */
+    protected $dateTime;
+
+    /**
+     * dateType
+     *
+     * @var int
+     */
+    protected $dateType;
+
+    /**
+     * Updates the Date and Time.
+     *
+     * @param \DateTime $dt
+     * @param int $dateType
+     * @return void
+     */
+    public function setDateTime(\DateTime $dt, $dateType = self::LOCALTZ) {
+
+        switch($dateType) {
+
+            case self::LOCAL :
+                $this->setValue($dt->format('Ymd\\THis'));
+                $this->offsetUnset('VALUE');
+                $this->offsetUnset('TZID');
+                $this->offsetSet('VALUE','DATE-TIME');
+                break;
+            case self::UTC :
+                $dt->setTimeZone(new \DateTimeZone('UTC'));
+                $this->setValue($dt->format('Ymd\\THis\\Z'));
+                $this->offsetUnset('VALUE');
+                $this->offsetUnset('TZID');
+                $this->offsetSet('VALUE','DATE-TIME');
+                break;
+            case self::LOCALTZ :
+                $this->setValue($dt->format('Ymd\\THis'));
+                $this->offsetUnset('VALUE');
+                $this->offsetUnset('TZID');
+                $this->offsetSet('VALUE','DATE-TIME');
+                $this->offsetSet('TZID', $dt->getTimeZone()->getName());
+                break;
+            case self::DATE :
+                $this->setValue($dt->format('Ymd'));
+                $this->offsetUnset('VALUE');
+                $this->offsetUnset('TZID');
+                $this->offsetSet('VALUE','DATE');
+                break;
+            default :
+                throw new \InvalidArgumentException('You must pass a valid dateType constant');
+
+        }
+        $this->dateTime = $dt;
+        $this->dateType = $dateType;
+
+    }
+
+    /**
+     * Returns the current DateTime value.
+     *
+     * If no value was set, this method returns null.
+     *
+     * @return \DateTime|null
+     */
+    public function getDateTime() {
+
+        if ($this->dateTime)
+            return $this->dateTime;
+
+        list(
+            $this->dateType,
+            $this->dateTime
+        ) = self::parseData($this->value, $this);
+        return $this->dateTime;
+
+    }
+
+    /**
+     * Returns the type of Date format.
+     *
+     * This method returns one of the format constants. If no date was set,
+     * this method will return null.
+     *
+     * @return int|null
+     */
+    public function getDateType() {
+
+        if ($this->dateType)
+            return $this->dateType;
+
+        list(
+            $this->dateType,
+            $this->dateTime,
+        ) = self::parseData($this->value, $this);
+        return $this->dateType;
+
+    }
+
+    /**
+     * This method will return true, if the property had a date and a time, as
+     * opposed to only a date.
+     *
+     * @return bool
+     */
+    public function hasTime() {
+
+        return $this->getDateType()!==self::DATE;
+
+    }
+
+    /**
+     * Parses the internal data structure to figure out what the current date
+     * and time is.
+     *
+     * The returned array contains two elements:
+     *   1. A 'DateType' constant (as defined on this class), or null.
+     *   2. A DateTime object (or null)
+     *
+     * @param string|null $propertyValue The string to parse (yymmdd or
+     *                                   ymmddThhmmss, etc..)
+     * @param \OldSabre\VObject\Property|null $property The instance of the
+     *                                              property we're parsing.
+     * @return array
+     */
+    static public function parseData($propertyValue, VObject\Property $property = null) {
+
+        if (is_null($propertyValue)) {
+            return array(null, null);
+        }
+
+        $date = '(?P<year>[1-2][0-9]{3})(?P<month>[0-1][0-9])(?P<date>[0-3][0-9])';
+        $time = '(?P<hour>[0-2][0-9])(?P<minute>[0-5][0-9])(?P<second>[0-5][0-9])';
+        $regex = "/^$date(T$time(?P<isutc>Z)?)?$/";
+
+        if (!preg_match($regex, $propertyValue, $matches)) {
+            throw new \InvalidArgumentException($propertyValue . ' is not a valid \DateTime or Date string');
+        }
+
+        if (!isset($matches['hour'])) {
+            // Date-only
+            return array(
+                self::DATE,
+                new \DateTime($matches['year'] . '-' . $matches['month'] . '-' . $matches['date'] . ' 00:00:00', new \DateTimeZone('UTC')),
+            );
+        }
+
+        $dateStr =
+            $matches['year'] .'-' .
+            $matches['month'] . '-' .
+            $matches['date'] . ' ' .
+            $matches['hour'] . ':' .
+            $matches['minute'] . ':' .
+            $matches['second'];
+
+        if (isset($matches['isutc'])) {
+            $dt = new \DateTime($dateStr,new \DateTimeZone('UTC'));
+            $dt->setTimeZone(new \DateTimeZone('UTC'));
+            return array(
+                self::UTC,
+                $dt
+            );
+        }
+
+        // Finding the timezone.
+        $tzid = $property['TZID'];
+        if (!$tzid) {
+            // This was a floating time string. This implies we use the
+            // timezone from date_default_timezone_set / date.timezone ini
+            // setting.
+            return array(
+                self::LOCAL,
+                new \DateTime($dateStr)
+            );
+        }
+
+        // To look up the timezone, we must first find the VCALENDAR component.
+        $root = $property;
+        while($root->parent) {
+            $root = $root->parent;
+        }
+        if ($root->name === 'VCALENDAR') {
+            $tz = VObject\TimeZoneUtil::getTimeZone((string)$tzid, $root);
+        } else {
+            $tz = VObject\TimeZoneUtil::getTimeZone((string)$tzid);
+        }
+
+        $dt = new \DateTime($dateStr, $tz);
+        $dt->setTimeZone($tz);
+
+        return array(
+            self::LOCALTZ,
+            $dt
+        );
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/MultiDateTime.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/MultiDateTime.php
new file mode 100644
index 0000000..363bc5d
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Property/MultiDateTime.php
@@ -0,0 +1,180 @@
+<?php
+
+namespace OldSabre\VObject\Property;
+
+use OldSabre\VObject;
+
+/**
+ * Multi-DateTime property
+ *
+ * This element is used for iCalendar properties such as the EXDATE property.
+ * It basically provides a few helper functions that make it easier to deal
+ * with these. It supports both DATE-TIME and DATE values.
+ *
+ * In order to use this correctly, you must call setDateTimes and getDateTimes
+ * to retrieve and modify dates respectively.
+ *
+ * If you use the 'value' or properties directly, this object does not keep
+ * reference and results might appear incorrectly.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class MultiDateTime extends VObject\Property {
+
+    /**
+     * DateTime representation
+     *
+     * @var DateTime[]
+     */
+    protected $dateTimes;
+
+    /**
+     * dateType
+     *
+     * This is one of the OldSabre\VObject\Property\DateTime constants.
+     *
+     * @var int
+     */
+    protected $dateType;
+
+    /**
+     * Updates the value
+     *
+     * @param array $dt Must be an array of DateTime objects.
+     * @param int $dateType
+     * @return void
+     */
+    public function setDateTimes(array $dt, $dateType = VObject\Property\DateTime::LOCALTZ) {
+
+        foreach($dt as $i)
+            if (!$i instanceof \DateTime)
+                throw new \InvalidArgumentException('You must pass an array of DateTime objects');
+
+        $this->offsetUnset('VALUE');
+        $this->offsetUnset('TZID');
+        switch($dateType) {
+
+            case DateTime::LOCAL :
+                $val = array();
+                foreach($dt as $i) {
+                    $val[] = $i->format('Ymd\\THis');
+                }
+                $this->setValue(implode(',',$val));
+                $this->offsetSet('VALUE','DATE-TIME');
+                break;
+            case DateTime::UTC :
+                $val = array();
+                foreach($dt as $i) {
+                    $i->setTimeZone(new \DateTimeZone('UTC'));
+                    $val[] = $i->format('Ymd\\THis\\Z');
+                }
+                $this->setValue(implode(',',$val));
+                $this->offsetSet('VALUE','DATE-TIME');
+                break;
+            case DateTime::LOCALTZ :
+                $val = array();
+                foreach($dt as $i) {
+                    $val[] = $i->format('Ymd\\THis');
+                }
+                $this->setValue(implode(',',$val));
+                $this->offsetSet('VALUE','DATE-TIME');
+                $this->offsetSet('TZID', $dt[0]->getTimeZone()->getName());
+                break;
+            case DateTime::DATE :
+                $val = array();
+                foreach($dt as $i) {
+                    $val[] = $i->format('Ymd');
+                }
+                $this->setValue(implode(',',$val));
+                $this->offsetSet('VALUE','DATE');
+                break;
+            default :
+                throw new \InvalidArgumentException('You must pass a valid dateType constant');
+
+        }
+        $this->dateTimes = $dt;
+        $this->dateType = $dateType;
+
+    }
+
+    /**
+     * Returns the current DateTime value.
+     *
+     * If no value was set, this method returns null.
+     *
+     * @return array|null
+     */
+    public function getDateTimes() {
+
+        if ($this->dateTimes)
+            return $this->dateTimes;
+
+        $dts = array();
+
+        if (!$this->value) {
+            $this->dateTimes = null;
+            $this->dateType = null;
+            return null;
+        }
+
+        foreach(explode(',',$this->value) as $val) {
+            list(
+                $type,
+                $dt
+            ) = DateTime::parseData($val, $this);
+            $dts[] = $dt;
+            $this->dateType = $type;
+        }
+        $this->dateTimes = $dts;
+        return $this->dateTimes;
+
+    }
+
+    /**
+     * Returns the type of Date format.
+     *
+     * This method returns one of the format constants. If no date was set,
+     * this method will return null.
+     *
+     * @return int|null
+     */
+    public function getDateType() {
+
+        if ($this->dateType)
+            return $this->dateType;
+
+        if (!$this->value) {
+            $this->dateTimes = null;
+            $this->dateType = null;
+            return null;
+        }
+
+        $dts = array();
+        foreach(explode(',',$this->value) as $val) {
+            list(
+                $type,
+                $dt
+            ) = DateTime::parseData($val, $this);
+            $dts[] = $dt;
+            $this->dateType = $type;
+        }
+        $this->dateTimes = $dts;
+        return $this->dateType;
+
+    }
+
+    /**
+     * This method will return true, if the property had a date and a time, as
+     * opposed to only a date.
+     *
+     * @return bool
+     */
+    public function hasTime() {
+
+        return $this->getDateType()!==DateTime::DATE;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Reader.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Reader.php
new file mode 100644
index 0000000..bc9bfc7
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Reader.php
@@ -0,0 +1,223 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * VCALENDAR/VCARD reader
+ *
+ * This class reads the vobject file, and returns a full element tree.
+ *
+ * TODO: this class currently completely works 'statically'. This is pointless,
+ * and defeats OOP principals. Needs refactoring in a future version.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Reader {
+
+    /**
+     * If this option is passed to the reader, it will be less strict about the
+     * validity of the lines.
+     *
+     * Currently using this option just means, that it will accept underscores
+     * in property names.
+     */
+    const OPTION_FORGIVING = 1;
+
+    /**
+     * If this option is turned on, any lines we cannot parse will be ignored
+     * by the reader.
+     */
+    const OPTION_IGNORE_INVALID_LINES = 2;
+
+    /**
+     * Parses the file and returns the top component
+     *
+     * The options argument is a bitfield. Pass any of the OPTIONS constant to
+     * alter the parsers' behaviour.
+     *
+     * @param string $data
+     * @param int $options
+     * @return Node
+     */
+    static function read($data, $options = 0) {
+
+        // Normalizing newlines
+        $data = str_replace(array("\r","\n\n"), array("\n","\n"), $data);
+
+        $lines = explode("\n", $data);
+
+        // Unfolding lines
+        $lines2 = array();
+        foreach($lines as $line) {
+
+            // Skipping empty lines
+            if (!$line) continue;
+
+            if ($line[0]===" " || $line[0]==="\t") {
+                $lines2[count($lines2)-1].=substr($line,1);
+            } else {
+                $lines2[] = $line;
+            }
+
+        }
+
+        unset($lines);
+
+        reset($lines2);
+
+        return self::readLine($lines2, $options);
+
+    }
+
+    /**
+     * Reads and parses a single line.
+     *
+     * This method receives the full array of lines. The array pointer is used
+     * to traverse.
+     *
+     * This method returns null if an invalid line was encountered, and the
+     * IGNORE_INVALID_LINES option was turned on.
+     *
+     * @param array $lines
+     * @param int $options See the OPTIONS constants.
+     * @return Node
+     */
+    static private function readLine(&$lines, $options = 0) {
+
+        $line = current($lines);
+        $lineNr = key($lines);
+        next($lines);
+
+        // Components
+        if (strtoupper(substr($line,0,6)) === "BEGIN:") {
+
+            $componentName = strtoupper(substr($line,6));
+            $obj = Component::create($componentName);
+
+            $nextLine = current($lines);
+
+            while(strtoupper(substr($nextLine,0,4))!=="END:") {
+
+                $parsedLine = self::readLine($lines, $options);
+                $nextLine = current($lines);
+
+                if (is_null($parsedLine)) {
+                    continue;
+                }
+                $obj->add($parsedLine);
+
+                if ($nextLine===false)
+                    throw new ParseException('Invalid VObject. Document ended prematurely.');
+
+            }
+
+            // Checking component name of the 'END:' line.
+            if (substr($nextLine,4)!==$obj->name) {
+                throw new ParseException('Invalid VObject, expected: "END:' . $obj->name . '" got: "' . $nextLine . '"');
+            }
+            next($lines);
+
+            return $obj;
+
+        }
+
+        // Properties
+        //$result = preg_match('/(?P<name>[A-Z0-9-]+)(?:;(?P<parameters>^(?<!:):))(.*)$/',$line,$matches);
+
+        if ($options & self::OPTION_FORGIVING) {
+            $token = '[A-Z0-9-\._]+';
+        } else {
+            $token = '[A-Z0-9-\.]+';
+        }
+        $parameters = "(?:;(?P<parameters>([^:^\"]|\"([^\"]*)\")*))?";
+        $regex = "/^(?P<name>$token)$parameters:(?P<value>.*)$/i";
+
+        $result = preg_match($regex,$line,$matches);
+
+        if (!$result) {
+            if ($options & self::OPTION_IGNORE_INVALID_LINES) {
+                return null;
+            } else {
+                throw new ParseException('Invalid VObject, line ' . ($lineNr+1) . ' did not follow the icalendar/vcard format');
+            }
+        }
+
+        $propertyName = strtoupper($matches['name']);
+        $propertyValue = preg_replace_callback('#(\\\\(\\\\|N|n))#',function($matches) {
+            if ($matches[2]==='n' || $matches[2]==='N') {
+                return "\n";
+            } else {
+                return $matches[2];
+            }
+        }, $matches['value']);
+
+        $obj = Property::create($propertyName, $propertyValue);
+
+        if ($matches['parameters']) {
+
+            foreach(self::readParameters($matches['parameters']) as $param) {
+                $obj->add($param);
+            }
+
+        }
+
+        return $obj;
+
+
+    }
+
+    /**
+     * Reads a parameter list from a property
+     *
+     * This method returns an array of Parameter
+     *
+     * @param string $parameters
+     * @return array
+     */
+    static private function readParameters($parameters) {
+
+        $token = '[A-Z0-9-]+';
+
+        $paramValue = '(?P<paramValue>[^\"^;]*|"[^"]*")';
+
+        $regex = "/(?<=^|;)(?P<paramName>$token)(=$paramValue(?=$|;))?/i";
+        preg_match_all($regex, $parameters, $matches,  PREG_SET_ORDER);
+
+        $params = array();
+        foreach($matches as $match) {
+
+            if (!isset($match['paramValue'])) {
+
+                $value = null;
+
+            } else {
+
+                $value = $match['paramValue'];
+
+                if (isset($value[0]) && $value[0]==='"') {
+                    // Stripping quotes, if needed
+                    $value = substr($value,1,strlen($value)-2);
+                }
+
+                $value = preg_replace_callback('#(\\\\(\\\\|N|n|;|,))#',function($matches) {
+                    if ($matches[2]==='n' || $matches[2]==='N') {
+                        return "\n";
+                    } else {
+                        return $matches[2];
+                    }
+                }, $value);
+
+            }
+
+            $params[] = new Parameter($match['paramName'], $value);
+
+        }
+
+        return $params;
+
+    }
+
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/RecurrenceIterator.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/RecurrenceIterator.php
new file mode 100644
index 0000000..64bd994
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/RecurrenceIterator.php
@@ -0,0 +1,1112 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * This class is used to determine new for a recurring event, when the next
+ * events occur.
+ *
+ * This iterator may loop infinitely in the future, therefore it is important
+ * that if you use this class, you set hard limits for the amount of iterations
+ * you want to handle.
+ *
+ * Note that currently there is not full support for the entire iCalendar
+ * specification, as it's very complex and contains a lot of permutations
+ * that's not yet used very often in software.
+ *
+ * For the focus has been on features as they actually appear in Calendaring
+ * software, but this may well get expanded as needed / on demand
+ *
+ * The following RRULE properties are supported
+ *   * UNTIL
+ *   * INTERVAL
+ *   * COUNT
+ *   * FREQ=DAILY
+ *     * BYDAY
+ *     * BYHOUR
+ *   * FREQ=WEEKLY
+ *     * BYDAY
+ *     * BYHOUR
+ *     * WKST
+ *   * FREQ=MONTHLY
+ *     * BYMONTHDAY
+ *     * BYDAY
+ *     * BYSETPOS
+ *   * FREQ=YEARLY
+ *     * BYMONTH
+ *     * BYMONTHDAY (only if BYMONTH is also set)
+ *     * BYDAY (only if BYMONTH is also set)
+ *
+ * Anything beyond this is 'undefined', which means that it may get ignored, or
+ * you may get unexpected results. The effect is that in some applications the
+ * specified recurrence may look incorrect, or is missing.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class RecurrenceIterator implements \Iterator {
+
+    /**
+     * The initial event date
+     *
+     * @var DateTime
+     */
+    public $startDate;
+
+    /**
+     * The end-date of the initial event
+     *
+     * @var DateTime
+     */
+    public $endDate;
+
+    /**
+     * The 'current' recurrence.
+     *
+     * This will be increased for every iteration.
+     *
+     * @var DateTime
+     */
+    public $currentDate;
+
+
+    /**
+     * List of dates that are excluded from the rules.
+     *
+     * This list contains the items that have been overriden by the EXDATE
+     * property.
+     *
+     * @var array
+     */
+    public $exceptionDates = array();
+
+    /**
+     * Base event
+     *
+     * @var Component\VEvent
+     */
+    public $baseEvent;
+
+    /**
+     * List of dates that are overridden by other events.
+     * Similar to $overriddenEvents, but this just contains the original dates.
+     *
+     * @var array
+     */
+    public $overriddenDates = array();
+
+    /**
+     * list of events that are 'overridden'.
+     *
+     * This is an array of Component\VEvent objects.
+     *
+     * @var array
+     */
+    public $overriddenEvents = array();
+
+
+    /**
+     * Frequency is one of: secondly, minutely, hourly, daily, weekly, monthly,
+     * yearly.
+     *
+     * @var string
+     */
+    public $frequency;
+
+    /**
+     * The last instance of this recurrence, inclusively
+     *
+     * @var DateTime|null
+     */
+    public $until;
+
+    /**
+     * The number of recurrences, or 'null' if infinitely recurring.
+     *
+     * @var int
+     */
+    public $count;
+
+    /**
+     * The interval.
+     *
+     * If for example frequency is set to daily, interval = 2 would mean every
+     * 2 days.
+     *
+     * @var int
+     */
+    public $interval = 1;
+
+    /**
+     * Which seconds to recur.
+     *
+     * This is an array of integers (between 0 and 60)
+     *
+     * @var array
+     */
+    public $bySecond;
+
+    /**
+     * Which minutes to recur
+     *
+     * This is an array of integers (between 0 and 59)
+     *
+     * @var array
+     */
+    public $byMinute;
+
+    /**
+     * Which hours to recur
+     *
+     * This is an array of integers (between 0 and 23)
+     *
+     * @var array
+     */
+    public $byHour;
+
+    /**
+     * Which weekdays to recur.
+     *
+     * This is an array of weekdays
+     *
+     * This may also be preceeded by a positive or negative integer. If present,
+     * this indicates the nth occurrence of a specific day within the monthly or
+     * yearly rrule. For instance, -2TU indicates the second-last tuesday of
+     * the month, or year.
+     *
+     * @var array
+     */
+    public $byDay;
+
+    /**
+     * Which days of the month to recur
+     *
+     * This is an array of days of the months (1-31). The value can also be
+     * negative. -5 for instance means the 5th last day of the month.
+     *
+     * @var array
+     */
+    public $byMonthDay;
+
+    /**
+     * Which days of the year to recur.
+     *
+     * This is an array with days of the year (1 to 366). The values can also
+     * be negative. For instance, -1 will always represent the last day of the
+     * year. (December 31st).
+     *
+     * @var array
+     */
+    public $byYearDay;
+
+    /**
+     * Which week numbers to recur.
+     *
+     * This is an array of integers from 1 to 53. The values can also be
+     * negative. -1 will always refer to the last week of the year.
+     *
+     * @var array
+     */
+    public $byWeekNo;
+
+    /**
+     * Which months to recur
+     *
+     * This is an array of integers from 1 to 12.
+     *
+     * @var array
+     */
+    public $byMonth;
+
+    /**
+     * Which items in an existing st to recur.
+     *
+     * These numbers work together with an existing by* rule. It specifies
+     * exactly which items of the existing by-rule to filter.
+     *
+     * Valid values are 1 to 366 and -1 to -366. As an example, this can be
+     * used to recur the last workday of the month.
+     *
+     * This would be done by setting frequency to 'monthly', byDay to
+     * 'MO,TU,WE,TH,FR' and bySetPos to -1.
+     *
+     * @var array
+     */
+    public $bySetPos;
+
+    /**
+     * When a week starts
+     *
+     * @var string
+     */
+    public $weekStart = 'MO';
+
+    /**
+     * The current item in the list
+     *
+     * @var int
+     */
+    public $counter = 0;
+
+    /**
+     * Simple mapping from iCalendar day names to day numbers
+     *
+     * @var array
+     */
+    private $dayMap = array(
+        'SU' => 0,
+        'MO' => 1,
+        'TU' => 2,
+        'WE' => 3,
+        'TH' => 4,
+        'FR' => 5,
+        'SA' => 6,
+    );
+
+    /**
+     * Mappings between the day number and english day name.
+     *
+     * @var array
+     */
+    private $dayNames = array(
+        0 => 'Sunday',
+        1 => 'Monday',
+        2 => 'Tuesday',
+        3 => 'Wednesday',
+        4 => 'Thursday',
+        5 => 'Friday',
+        6 => 'Saturday',
+    );
+
+    /**
+     * If the current iteration of the event is an overriden event, this
+     * property will hold the VObject
+     *
+     * @var Component
+     */
+    private $currentOverriddenEvent;
+
+    /**
+     * This property may contain the date of the next not-overridden event.
+     * This date is calculated sometimes a bit early, before overridden events
+     * are evaluated.
+     *
+     * @var DateTime
+     */
+    private $nextDate;
+
+    /**
+     * Creates the iterator
+     *
+     * You should pass a VCALENDAR component, as well as the UID of the event
+     * we're going to traverse.
+     *
+     * @param Component $vcal
+     * @param string|null $uid
+     */
+    public function __construct(Component $vcal, $uid=null) {
+
+        if (is_null($uid)) {
+            if ($vcal->name === 'VCALENDAR') {
+                throw new \InvalidArgumentException('If you pass a VCALENDAR object, you must pass a uid argument as well');
+            }
+            $components = array($vcal);
+            $uid = (string)$vcal->uid;
+        } else {
+            $components = $vcal->select('VEVENT');
+        }
+        foreach($components as $component) {
+            if ((string)$component->uid == $uid) {
+                if (isset($component->{'RECURRENCE-ID'})) {
+                    $this->overriddenEvents[$component->DTSTART->getDateTime()->getTimeStamp()] = $component;
+                    $this->overriddenDates[] = $component->{'RECURRENCE-ID'}->getDateTime();
+                } else {
+                    $this->baseEvent = $component;
+                }
+            }
+        }
+        if (!$this->baseEvent) {
+            throw new \InvalidArgumentException('Could not find a base event with uid: ' . $uid);
+        }
+
+        $this->startDate = clone $this->baseEvent->DTSTART->getDateTime();
+
+        $this->endDate = null;
+        if (isset($this->baseEvent->DTEND)) {
+            $this->endDate = clone $this->baseEvent->DTEND->getDateTime();
+        } else {
+            $this->endDate = clone $this->startDate;
+            if (isset($this->baseEvent->DURATION)) {
+                $this->endDate->add(DateTimeParser::parse($this->baseEvent->DURATION->value));
+            } elseif ($this->baseEvent->DTSTART->getDateType()===Property\DateTime::DATE) {
+                $this->endDate->modify('+1 day');
+            }
+        }
+        $this->currentDate = clone $this->startDate;
+
+        $rrule = (string)$this->baseEvent->RRULE;
+
+        $parts = explode(';', $rrule);
+
+        // If no rrule was specified, we create a default setting
+        if (!$rrule) {
+            $this->frequency = 'daily';
+            $this->count = 1;
+        } else foreach($parts as $part) {
+
+            list($key, $value) = explode('=', $part, 2);
+
+            switch(strtoupper($key)) {
+
+                case 'FREQ' :
+                    if (!in_array(
+                        strtolower($value),
+                        array('secondly','minutely','hourly','daily','weekly','monthly','yearly')
+                    )) {
+                        throw new \InvalidArgumentException('Unknown value for FREQ=' . strtoupper($value));
+
+                    }
+                    $this->frequency = strtolower($value);
+                    break;
+
+                case 'UNTIL' :
+                    $this->until = DateTimeParser::parse($value);
+
+                    // In some cases events are generated with an UNTIL=
+                    // parameter before the actual start of the event.
+                    //
+                    // Not sure why this is happening. We assume that the
+                    // intention was that the event only recurs once.
+                    //
+                    // So we are modifying the parameter so our code doesn't
+                    // break.
+                    if($this->until < $this->baseEvent->DTSTART->getDateTime()) {
+                        $this->until = $this->baseEvent->DTSTART->getDateTime();
+                    }
+                    break;
+
+                case 'COUNT' :
+                    $this->count = (int)$value;
+                    break;
+
+                case 'INTERVAL' :
+                    $this->interval = (int)$value;
+                    if ($this->interval < 1) {
+                        throw new \InvalidArgumentException('INTERVAL in RRULE must be a positive integer!');
+                    }
+                    break;
+
+                case 'BYSECOND' :
+                    $this->bySecond = explode(',', $value);
+                    break;
+
+                case 'BYMINUTE' :
+                    $this->byMinute = explode(',', $value);
+                    break;
+
+                case 'BYHOUR' :
+                    $this->byHour = explode(',', $value);
+                    break;
+
+                case 'BYDAY' :
+                    $this->byDay = explode(',', strtoupper($value));
+                    break;
+
+                case 'BYMONTHDAY' :
+                    $this->byMonthDay = explode(',', $value);
+                    break;
+
+                case 'BYYEARDAY' :
+                    $this->byYearDay = explode(',', $value);
+                    break;
+
+                case 'BYWEEKNO' :
+                    $this->byWeekNo = explode(',', $value);
+                    break;
+
+                case 'BYMONTH' :
+                    $this->byMonth = explode(',', $value);
+                    break;
+
+                case 'BYSETPOS' :
+                    $this->bySetPos = explode(',', $value);
+                    break;
+
+                case 'WKST' :
+                    $this->weekStart = strtoupper($value);
+                    break;
+
+            }
+
+        }
+
+        // Parsing exception dates
+        if (isset($this->baseEvent->EXDATE)) {
+            foreach($this->baseEvent->EXDATE as $exDate) {
+
+                foreach(explode(',', (string)$exDate) as $exceptionDate) {
+
+                    $this->exceptionDates[] =
+                        DateTimeParser::parse($exceptionDate, $this->startDate->getTimeZone());
+
+                }
+
+            }
+
+        }
+
+    }
+
+    /**
+     * Returns the current item in the list
+     *
+     * @return DateTime
+     */
+    public function current() {
+
+        if (!$this->valid()) return null;
+        return clone $this->currentDate;
+
+    }
+
+    /**
+     * This method returns the startdate for the current iteration of the
+     * event.
+     *
+     * @return DateTime
+     */
+    public function getDtStart() {
+
+        if (!$this->valid()) return null;
+        return clone $this->currentDate;
+
+    }
+
+    /**
+     * This method returns the enddate for the current iteration of the
+     * event.
+     *
+     * @return DateTime
+     */
+    public function getDtEnd() {
+
+        if (!$this->valid()) return null;
+        $dtEnd = clone $this->currentDate;
+        $dtEnd->add( $this->startDate->diff( $this->endDate ) );
+        return clone $dtEnd;
+
+    }
+
+    /**
+     * Returns a VEVENT object with the updated start and end date.
+     *
+     * Any recurrence information is removed, and this function may return an
+     * 'overridden' event instead.
+     *
+     * This method always returns a cloned instance.
+     *
+     * @return Component\VEvent
+     */
+    public function getEventObject() {
+
+        if ($this->currentOverriddenEvent) {
+            return clone $this->currentOverriddenEvent;
+        }
+        $event = clone $this->baseEvent;
+        unset($event->RRULE);
+        unset($event->EXDATE);
+        unset($event->RDATE);
+        unset($event->EXRULE);
+
+        $event->DTSTART->setDateTime($this->getDTStart(), $event->DTSTART->getDateType());
+        if (isset($event->DTEND)) {
+            $event->DTEND->setDateTime($this->getDtEnd(), $event->DTSTART->getDateType());
+        }
+        if ($this->counter > 0) {
+            $event->{'RECURRENCE-ID'} = (string)$event->DTSTART;
+        }
+
+        return $event;
+
+    }
+
+    /**
+     * Returns the current item number
+     *
+     * @return int
+     */
+    public function key() {
+
+        return $this->counter;
+
+    }
+
+    /**
+     * Whether or not there is a 'next item'
+     *
+     * @return bool
+     */
+    public function valid() {
+
+        if (!is_null($this->count)) {
+            return $this->counter < $this->count;
+        }
+        if (!is_null($this->until)) {
+            return $this->currentDate <= $this->until;
+        }
+        return true;
+
+    }
+
+    /**
+     * Resets the iterator
+     *
+     * @return void
+     */
+    public function rewind() {
+
+        $this->currentDate = clone $this->startDate;
+        $this->counter = 0;
+
+    }
+
+    /**
+     * This method allows you to quickly go to the next occurrence after the
+     * specified date.
+     *
+     * Note that this checks the current 'endDate', not the 'stardDate'. This
+     * means that if you forward to January 1st, the iterator will stop at the
+     * first event that ends *after* January 1st.
+     *
+     * @param DateTime $dt
+     * @return void
+     */
+    public function fastForward(\DateTime $dt) {
+
+        while($this->valid() && $this->getDTEnd() <= $dt) {
+            $this->next();
+        }
+
+    }
+
+    /**
+     * Returns true if this recurring event never ends.
+     *
+     * @return bool
+     */
+    public function isInfinite() {
+
+        return !$this->count && !$this->until;
+
+    }
+
+    /**
+     * Goes on to the next iteration
+     *
+     * @return void
+     */
+    public function next() {
+
+        /*
+        if (!is_null($this->count) && $this->counter >= $this->count) {
+            $this->currentDate = null;
+        }*/
+
+
+        $previousStamp = $this->currentDate->getTimeStamp();
+
+        while(true) {
+
+            $this->currentOverriddenEvent = null;
+
+            // If we have a next date 'stored', we use that
+            if ($this->nextDate) {
+                $this->currentDate = $this->nextDate;
+                $currentStamp = $this->currentDate->getTimeStamp();
+                $this->nextDate = null;
+            } else {
+
+                // Otherwise, we calculate it
+                switch($this->frequency) {
+
+                    case 'hourly' :
+                        $this->nextHourly();
+                        break;
+
+                    case 'daily' :
+                        $this->nextDaily();
+                        break;
+
+                    case 'weekly' :
+                        $this->nextWeekly();
+                        break;
+
+                    case 'monthly' :
+                        $this->nextMonthly();
+                        break;
+
+                    case 'yearly' :
+                        $this->nextYearly();
+                        break;
+
+                }
+                $currentStamp = $this->currentDate->getTimeStamp();
+
+                // Checking exception dates
+                foreach($this->exceptionDates as $exceptionDate) {
+                    if ($this->currentDate == $exceptionDate) {
+                        $this->counter++;
+                        continue 2;
+                    }
+                }
+                foreach($this->overriddenDates as $overriddenDate) {
+                    if ($this->currentDate == $overriddenDate) {
+                        continue 2;
+                    }
+                }
+
+            }
+
+            // Checking overridden events
+            foreach($this->overriddenEvents as $index=>$event) {
+                if ($index > $previousStamp && $index <= $currentStamp) {
+
+                    // We're moving the 'next date' aside, for later use.
+                    $this->nextDate = clone $this->currentDate;
+
+                    $this->currentDate = $event->DTSTART->getDateTime();
+                    $this->currentOverriddenEvent = $event;
+
+                    break;
+                }
+            }
+
+            break;
+
+        }
+
+        /*
+        if (!is_null($this->until)) {
+            if($this->currentDate > $this->until) {
+                $this->currentDate = null;
+            }
+        }*/
+
+        $this->counter++;
+
+    }
+
+    /**
+     * Does the processing for advancing the iterator for hourly frequency.
+     *
+     * @return void
+     */
+    protected function nextHourly() {
+
+        if (!$this->byHour) {
+            $this->currentDate->modify('+' . $this->interval . ' hours');
+            return;
+        }
+    }
+
+    /**
+     * Does the processing for advancing the iterator for daily frequency.
+     *
+     * @return void
+     */
+    protected function nextDaily() {
+
+        if (!$this->byHour && !$this->byDay) {
+            $this->currentDate->modify('+' . $this->interval . ' days');
+            return;
+        }
+
+        if (isset($this->byHour)) {
+            $recurrenceHours = $this->getHours();
+        }
+
+        if (isset($this->byDay)) {
+            $recurrenceDays = $this->getDays();
+        }
+
+        do {
+
+            if ($this->byHour) {
+                if ($this->currentDate->format('G') == '23') {
+                    // to obey the interval rule
+                    $this->currentDate->modify('+' . $this->interval-1 . ' days');
+                }
+
+                $this->currentDate->modify('+1 hours');
+
+            } else {
+                $this->currentDate->modify('+' . $this->interval . ' days');
+
+            }
+
+            // Current day of the week
+            $currentDay = $this->currentDate->format('w');
+
+            // Current hour of the day
+            $currentHour = $this->currentDate->format('G');
+
+        } while (($this->byDay && !in_array($currentDay, $recurrenceDays)) || ($this->byHour && !in_array($currentHour, $recurrenceHours)));
+
+    }
+
+    /**
+     * Does the processing for advancing the iterator for weekly frequency.
+     *
+     * @return void
+     */
+    protected function nextWeekly() {
+
+        if (!$this->byHour && !$this->byDay) {
+            $this->currentDate->modify('+' . $this->interval . ' weeks');
+            return;
+        }
+
+        if ($this->byHour) {
+            $recurrenceHours = $this->getHours();
+        }
+
+        if ($this->byDay) {
+            $recurrenceDays = $this->getDays();
+        }
+
+        // First day of the week:
+        $firstDay = $this->dayMap[$this->weekStart];
+
+        do {
+
+            if ($this->byHour) {
+                $this->currentDate->modify('+1 hours');
+            } else {
+                $this->currentDate->modify('+1 days');
+            }
+
+            // Current day of the week
+            $currentDay = (int) $this->currentDate->format('w');
+
+            // Current hour of the day
+            $currentHour = (int) $this->currentDate->format('G');
+
+            // We need to roll over to the next week
+            if ($currentDay === $firstDay && (!$this->byHour || $currentHour == '0')) {
+                $this->currentDate->modify('+' . $this->interval-1 . ' weeks');
+
+                // We need to go to the first day of this week, but only if we
+                // are not already on this first day of this week.
+                if($this->currentDate->format('w') != $firstDay) {
+                    $this->currentDate->modify('last ' . $this->dayNames[$this->dayMap[$this->weekStart]]);
+                }
+            }
+
+            // We have a match
+        } while (($this->byDay && !in_array($currentDay, $recurrenceDays)) || ($this->byHour && !in_array($currentHour, $recurrenceHours)));
+    }
+
+    /**
+     * Does the processing for advancing the iterator for monthly frequency.
+     *
+     * @return void
+     */
+    protected function nextMonthly() {
+
+        $currentDayOfMonth = $this->currentDate->format('j');
+        if (!$this->byMonthDay && !$this->byDay) {
+
+            // If the current day is higher than the 28th, rollover can
+            // occur to the next month. We Must skip these invalid
+            // entries.
+            if ($currentDayOfMonth < 29) {
+                $this->currentDate->modify('+' . $this->interval . ' months');
+            } else {
+                $increase = 0;
+                do {
+                    $increase++;
+                    $tempDate = clone $this->currentDate;
+                    $tempDate->modify('+ ' . ($this->interval*$increase) . ' months');
+                } while ($tempDate->format('j') != $currentDayOfMonth);
+                $this->currentDate = $tempDate;
+            }
+            return;
+        }
+
+        while(true) {
+
+            $occurrences = $this->getMonthlyOccurrences();
+
+            foreach($occurrences as $occurrence) {
+
+                // The first occurrence thats higher than the current
+                // day of the month wins.
+                if ($occurrence > $currentDayOfMonth) {
+                    break 2;
+                }
+
+            }
+
+            // If we made it all the way here, it means there were no
+            // valid occurrences, and we need to advance to the next
+            // month.
+            $this->currentDate->modify('first day of this month');
+            $this->currentDate->modify('+ ' . $this->interval . ' months');
+
+            // This goes to 0 because we need to start counting at hte
+            // beginning.
+            $currentDayOfMonth = 0;
+
+        }
+
+        $this->currentDate->setDate($this->currentDate->format('Y'), $this->currentDate->format('n'), $occurrence);
+
+    }
+
+    /**
+     * Does the processing for advancing the iterator for yearly frequency.
+     *
+     * @return void
+     */
+    protected function nextYearly() {
+
+        $currentMonth = $this->currentDate->format('n');
+        $currentYear = $this->currentDate->format('Y');
+        $currentDayOfMonth = $this->currentDate->format('j');
+
+        // No sub-rules, so we just advance by year
+        if (!$this->byMonth) {
+
+            // Unless it was a leap day!
+            if ($currentMonth==2 && $currentDayOfMonth==29) {
+
+                $counter = 0;
+                do {
+                    $counter++;
+                    // Here we increase the year count by the interval, until
+                    // we hit a date that's also in a leap year.
+                    //
+                    // We could just find the next interval that's dividable by
+                    // 4, but that would ignore the rule that there's no leap
+                    // year every year that's dividable by a 100, but not by
+                    // 400. (1800, 1900, 2100). So we just rely on the datetime
+                    // functions instead.
+                    $nextDate = clone $this->currentDate;
+                    $nextDate->modify('+ ' . ($this->interval*$counter) . ' years');
+                } while ($nextDate->format('n')!=2);
+                $this->currentDate = $nextDate;
+
+                return;
+
+            }
+
+            // The easiest form
+            $this->currentDate->modify('+' . $this->interval . ' years');
+            return;
+
+        }
+
+        $currentMonth = $this->currentDate->format('n');
+        $currentYear = $this->currentDate->format('Y');
+        $currentDayOfMonth = $this->currentDate->format('j');
+
+        $advancedToNewMonth = false;
+
+        // If we got a byDay or getMonthDay filter, we must first expand
+        // further.
+        if ($this->byDay || $this->byMonthDay) {
+
+            while(true) {
+
+                $occurrences = $this->getMonthlyOccurrences();
+
+                foreach($occurrences as $occurrence) {
+
+                    // The first occurrence that's higher than the current
+                    // day of the month wins.
+                    // If we advanced to the next month or year, the first
+                    // occurrence is always correct.
+                    if ($occurrence > $currentDayOfMonth || $advancedToNewMonth) {
+                        break 2;
+                    }
+
+                }
+
+                // If we made it here, it means we need to advance to
+                // the next month or year.
+                $currentDayOfMonth = 1;
+                $advancedToNewMonth = true;
+                do {
+
+                    $currentMonth++;
+                    if ($currentMonth>12) {
+                        $currentYear+=$this->interval;
+                        $currentMonth = 1;
+                    }
+                } while (!in_array($currentMonth, $this->byMonth));
+
+                $this->currentDate->setDate($currentYear, $currentMonth, $currentDayOfMonth);
+
+            }
+
+            // If we made it here, it means we got a valid occurrence
+            $this->currentDate->setDate($currentYear, $currentMonth, $occurrence);
+            return;
+
+        } else {
+
+            // These are the 'byMonth' rules, if there are no byDay or
+            // byMonthDay sub-rules.
+            do {
+
+                $currentMonth++;
+                if ($currentMonth>12) {
+                    $currentYear+=$this->interval;
+                    $currentMonth = 1;
+                }
+            } while (!in_array($currentMonth, $this->byMonth));
+            $this->currentDate->setDate($currentYear, $currentMonth, $currentDayOfMonth);
+
+            return;
+
+        }
+
+    }
+
+    /**
+     * Returns all the occurrences for a monthly frequency with a 'byDay' or
+     * 'byMonthDay' expansion for the current month.
+     *
+     * The returned list is an array of integers with the day of month (1-31).
+     *
+     * @return array
+     */
+    protected function getMonthlyOccurrences() {
+
+        $startDate = clone $this->currentDate;
+
+        $byDayResults = array();
+
+        // Our strategy is to simply go through the byDays, advance the date to
+        // that point and add it to the results.
+        if ($this->byDay) foreach($this->byDay as $day) {
+
+            $dayName = $this->dayNames[$this->dayMap[substr($day,-2)]];
+
+            // Dayname will be something like 'wednesday'. Now we need to find
+            // all wednesdays in this month.
+            $dayHits = array();
+
+            $checkDate = clone $startDate;
+            $checkDate->modify('first day of this month');
+            $checkDate->modify($dayName);
+
+            do {
+                $dayHits[] = $checkDate->format('j');
+                $checkDate->modify('next ' . $dayName);
+            } while ($checkDate->format('n') === $startDate->format('n'));
+
+            // So now we have 'all wednesdays' for month. It is however
+            // possible that the user only really wanted the 1st, 2nd or last
+            // wednesday.
+            if (strlen($day)>2) {
+                $offset = (int)substr($day,0,-2);
+
+                if ($offset>0) {
+                    // It is possible that the day does not exist, such as a
+                    // 5th or 6th wednesday of the month.
+                    if (isset($dayHits[$offset-1])) {
+                        $byDayResults[] = $dayHits[$offset-1];
+                    }
+                } else {
+
+                    // if it was negative we count from the end of the array
+                    $byDayResults[] = $dayHits[count($dayHits) + $offset];
+                }
+            } else {
+                // There was no counter (first, second, last wednesdays), so we
+                // just need to add the all to the list).
+                $byDayResults = array_merge($byDayResults, $dayHits);
+
+            }
+
+        }
+
+        $byMonthDayResults = array();
+        if ($this->byMonthDay) foreach($this->byMonthDay as $monthDay) {
+
+            // Removing values that are out of range for this month
+            if ($monthDay > $startDate->format('t') ||
+                $monthDay < 0-$startDate->format('t')) {
+                    continue;
+            }
+            if ($monthDay>0) {
+                $byMonthDayResults[] = $monthDay;
+            } else {
+                // Negative values
+                $byMonthDayResults[] = $startDate->format('t') + 1 + $monthDay;
+            }
+        }
+
+        // If there was just byDay or just byMonthDay, they just specify our
+        // (almost) final list. If both were provided, then byDay limits the
+        // list.
+        if ($this->byMonthDay && $this->byDay) {
+            $result = array_intersect($byMonthDayResults, $byDayResults);
+        } elseif ($this->byMonthDay) {
+            $result = $byMonthDayResults;
+        } else {
+            $result = $byDayResults;
+        }
+        $result = array_unique($result);
+        sort($result, SORT_NUMERIC);
+
+        // The last thing that needs checking is the BYSETPOS. If it's set, it
+        // means only certain items in the set survive the filter.
+        if (!$this->bySetPos) {
+            return $result;
+        }
+
+        $filteredResult = array();
+        foreach($this->bySetPos as $setPos) {
+
+            if ($setPos<0) {
+                $setPos = count($result)-($setPos+1);
+            }
+            if (isset($result[$setPos-1])) {
+                $filteredResult[] = $result[$setPos-1];
+            }
+        }
+
+        sort($filteredResult, SORT_NUMERIC);
+        return $filteredResult;
+
+    }
+
+    protected function getHours()
+    {
+        $recurrenceHours = array();
+        foreach($this->byHour as $byHour) {
+            $recurrenceHours[] = $byHour;
+        }
+
+        return $recurrenceHours;
+    }
+
+    protected function getDays()
+    {
+        $recurrenceDays = array();
+        foreach($this->byDay as $byDay) {
+
+            // The day may be preceeded with a positive (+n) or
+            // negative (-n) integer. However, this does not make
+            // sense in 'weekly' so we ignore it here.
+            $recurrenceDays[] = $this->dayMap[substr($byDay,-2)];
+
+        }
+
+        return $recurrenceDays;
+    }
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/ICalendar.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/ICalendar.php
new file mode 100644
index 0000000..20b8f42
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/ICalendar.php
@@ -0,0 +1,111 @@
+<?php
+
+namespace OldSabre\VObject\Splitter;
+
+use OldSabre\VObject;
+
+/**
+ * Splitter
+ *
+ * This class is responsible for splitting up iCalendar objects.
+ *
+ * This class expects a single VCALENDAR object with one or more
+ * calendar-objects inside. Objects with identical UID's will be combined into
+ * a single object.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Dominik Tobschall
+ * @author Armin Hackmann
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class ICalendar implements SplitterInterface {
+
+    /**
+     * Timezones
+     *
+     * @var array
+     */
+    protected $vtimezones = array();
+
+    /**
+     * iCalendar objects
+     *
+     * @var array
+     */
+    protected $objects = array();
+
+    /**
+     * Constructor
+     *
+     * The splitter should receive an readable file stream as it's input.
+     *
+     * @param resource $input
+     */
+    public function __construct($input) {
+
+        $data = VObject\Reader::read(stream_get_contents($input));
+        $vtimezones = array();
+        $components = array();
+
+        foreach($data->children as $component) {
+            if (!$component instanceof VObject\Component) {
+                continue;
+            }
+
+            // Get all timezones
+            if ($component->name === 'VTIMEZONE') {
+                $this->vtimezones[(string)$component->TZID] = $component;
+                continue;
+            }
+
+            // Get component UID for recurring Events search
+            if($component->UID) {
+                $uid = (string)$component->UID;
+            } else {
+                // Generating a random UID
+                $uid = sha1(microtime()) . '-vobjectimport';
+            }
+
+            // Take care of recurring events
+            if (!array_key_exists($uid, $this->objects)) {
+                $this->objects[$uid] = VObject\Component::create('VCALENDAR');
+            }
+
+            $this->objects[$uid]->add(clone $component);
+        }
+
+    }
+
+    /**
+     * Every time getNext() is called, a new object will be parsed, until we
+     * hit the end of the stream.
+     *
+     * When the end is reached, null will be returned.
+     *
+     * @return OldSabre\VObject\Component|null
+     */
+    public function getNext() {
+
+        if($object=array_shift($this->objects)) {
+
+            // create our baseobject
+            $object->version = '2.0';
+            $object->prodid = '-//Sabre//Sabre VObject ' . VObject\Version::VERSION . '//EN';
+            $object->calscale = 'GREGORIAN';
+
+            // add vtimezone information to obj (if we have it)
+            foreach ($this->vtimezones as $vtimezone) {
+                $object->add($vtimezone);
+            }
+
+            return $object;
+
+        } else {
+
+            return null;
+
+        }
+
+   }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/SplitterInterface.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/SplitterInterface.php
new file mode 100644
index 0000000..3696031
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/SplitterInterface.php
@@ -0,0 +1,39 @@
+<?php
+
+namespace OldSabre\VObject\Splitter;
+
+/**
+ * VObject splitter
+ *
+ * The splitter is responsible for reading a large vCard or iCalendar object,
+ * and splitting it into multiple objects.
+ *
+ * This is for example for Card and CalDAV, which require every event and vcard
+ * to exist in their own objects, instead of one large one.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Dominik Tobschall
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+interface SplitterInterface {
+
+    /**
+     * Constructor
+     *
+     * The splitter should receive an readable file stream as it's input.
+     *
+     * @param resource $input
+     */
+    function __construct($input);
+
+    /**
+     * Every time getNext() is called, a new object will be parsed, until we
+     * hit the end of the stream.
+     *
+     * When the end is reached, null will be returned.
+     *
+     * @return OldSabre\VObject\Component|null
+     */
+    function getNext();
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/VCard.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/VCard.php
new file mode 100644
index 0000000..fc5e39b
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Splitter/VCard.php
@@ -0,0 +1,76 @@
+<?php
+
+namespace OldSabre\VObject\Splitter;
+
+use OldSabre\VObject;
+
+/**
+ * Splitter
+ *
+ * This class is responsible for splitting up VCard objects.
+ *
+ * It is assumed that the input stream contains 1 or more VCARD objects. This
+ * class checks for BEGIN:VCARD and END:VCARD and parses each encountered
+ * component individually.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Dominik Tobschall
+ * @author Armin Hackmann
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class VCard implements SplitterInterface {
+
+    /**
+     * File handle
+     *
+     * @var resource
+     */
+    protected $input;
+
+    /**
+     * Constructor
+     *
+     * The splitter should receive an readable file stream as it's input.
+     *
+     * @param resource $input
+     */
+    public function __construct($input) {
+
+        $this->input = $input;
+
+    }
+
+    /**
+     * Every time getNext() is called, a new object will be parsed, until we
+     * hit the end of the stream.
+     *
+     * When the end is reached, null will be returned.
+     *
+     * @return OldSabre\VObject\Component|null
+     */
+    public function getNext() {
+
+        $vcard = '';
+
+        do {
+
+            if (feof($this->input)) {
+                return false;
+            }
+
+            $line = fgets($this->input);
+            $vcard .= $line;
+
+        } while(strtoupper(substr($line,0,4))!=="END:");
+
+        $object = VObject\Reader::read($vcard);
+
+        if($object->name !== 'VCARD') {
+            throw new \InvalidArgumentException("Thats no vCard!", 1);
+        }
+
+        return $object;
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/StringUtil.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/StringUtil.php
new file mode 100644
index 0000000..1218792
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/StringUtil.php
@@ -0,0 +1,61 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * Useful utilities for working with various strings.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class StringUtil {
+
+    /**
+     * Returns true or false depending on if a string is valid UTF-8
+     *
+     * @param string $str
+     * @return bool
+     */
+    static function isUTF8($str) {
+
+        // First check.. mb_check_encoding
+        if (!mb_check_encoding($str, 'UTF-8')) {
+            return false;
+        }
+
+        // Control characters
+        if (preg_match('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', $str)) {
+            return false;
+        }
+
+        return true;
+
+    }
+
+    /**
+     * This method tries its best to convert the input string to UTF-8.
+     *
+     * Currently only ISO-5991-1 input and UTF-8 input is supported, but this
+     * may be expanded upon if we receive other examples.
+     *
+     * @param string $str
+     * @return string
+     */
+    static function convertToUTF8($str) {
+
+        $encoding = mb_detect_encoding($str , array('UTF-8','ISO-8859-1'), true);
+
+        if ($encoding === 'ISO-8859-1') {
+            $newStr = utf8_encode($str);
+        } else {
+            $newStr = $str;
+        }
+
+        // Removing any control characters
+        return (preg_replace('%(?:[\x00-\x08\x0B-\x0C\x0E\x0F])%', '', $newStr));
+
+    }
+
+}
+
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/TimeZoneUtil.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/TimeZoneUtil.php
new file mode 100644
index 0000000..dbb77b0
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/TimeZoneUtil.php
@@ -0,0 +1,482 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * Time zone name translation
+ *
+ * This file translates well-known time zone names into "Olson database" time zone names.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Frank Edelhaeuser (fedel@users.sourceforge.net)
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class TimeZoneUtil {
+
+    public static $map = array(
+
+        // from http://unicode.org/repos/cldr-tmp/trunk/diff/supplemental/zone_tzid.html
+        // snapshot taken on 2012/01/16
+
+        // windows
+        'AUS Central Standard Time'=>'Australia/Darwin',
+        'AUS Eastern Standard Time'=>'Australia/Sydney',
+        'Afghanistan Standard Time'=>'Asia/Kabul',
+        'Alaskan Standard Time'=>'America/Anchorage',
+        'Arab Standard Time'=>'Asia/Riyadh',
+        'Arabian Standard Time'=>'Asia/Dubai',
+        'Arabic Standard Time'=>'Asia/Baghdad',
+        'Argentina Standard Time'=>'America/Buenos_Aires',
+        'Armenian Standard Time'=>'Asia/Yerevan',
+        'Atlantic Standard Time'=>'America/Halifax',
+        'Azerbaijan Standard Time'=>'Asia/Baku',
+        'Azores Standard Time'=>'Atlantic/Azores',
+        'Bangladesh Standard Time'=>'Asia/Dhaka',
+        'Canada Central Standard Time'=>'America/Regina',
+        'Cape Verde Standard Time'=>'Atlantic/Cape_Verde',
+        'Caucasus Standard Time'=>'Asia/Yerevan',
+        'Cen. Australia Standard Time'=>'Australia/Adelaide',
+        'Central America Standard Time'=>'America/Guatemala',
+        'Central Asia Standard Time'=>'Asia/Almaty',
+        'Central Brazilian Standard Time'=>'America/Cuiaba',
+        'Central Europe Standard Time'=>'Europe/Budapest',
+        'Central European Standard Time'=>'Europe/Warsaw',
+        'Central Pacific Standard Time'=>'Pacific/Guadalcanal',
+        'Central Standard Time'=>'America/Chicago',
+        'Central Standard Time (Mexico)'=>'America/Mexico_City',
+        'China Standard Time'=>'Asia/Shanghai',
+        'Dateline Standard Time'=>'Etc/GMT+12',
+        'E. Africa Standard Time'=>'Africa/Nairobi',
+        'E. Australia Standard Time'=>'Australia/Brisbane',
+        'E. Europe Standard Time'=>'Europe/Minsk',
+        'E. South America Standard Time'=>'America/Sao_Paulo',
+        'Eastern Standard Time'=>'America/New_York',
+        'Egypt Standard Time'=>'Africa/Cairo',
+        'Ekaterinburg Standard Time'=>'Asia/Yekaterinburg',
+        'FLE Standard Time'=>'Europe/Kiev',
+        'Fiji Standard Time'=>'Pacific/Fiji',
+        'GMT Standard Time'=>'Europe/London',
+        'GTB Standard Time'=>'Europe/Istanbul',
+        'Georgian Standard Time'=>'Asia/Tbilisi',
+        'Greenland Standard Time'=>'America/Godthab',
+        'Greenwich Standard Time'=>'Atlantic/Reykjavik',
+        'Hawaiian Standard Time'=>'Pacific/Honolulu',
+        'India Standard Time'=>'Asia/Calcutta',
+        'Iran Standard Time'=>'Asia/Tehran',
+        'Israel Standard Time'=>'Asia/Jerusalem',
+        'Jordan Standard Time'=>'Asia/Amman',
+        'Kamchatka Standard Time'=>'Asia/Kamchatka',
+        'Korea Standard Time'=>'Asia/Seoul',
+        'Magadan Standard Time'=>'Asia/Magadan',
+        'Mauritius Standard Time'=>'Indian/Mauritius',
+        'Mexico Standard Time'=>'America/Mexico_City',
+        'Mexico Standard Time 2'=>'America/Chihuahua',
+        'Mid-Atlantic Standard Time'=>'Etc/GMT-2',
+        'Middle East Standard Time'=>'Asia/Beirut',
+        'Montevideo Standard Time'=>'America/Montevideo',
+        'Morocco Standard Time'=>'Africa/Casablanca',
+        'Mountain Standard Time'=>'America/Denver',
+        'Mountain Standard Time (Mexico)'=>'America/Chihuahua',
+        'Myanmar Standard Time'=>'Asia/Rangoon',
+        'N. Central Asia Standard Time'=>'Asia/Novosibirsk',
+        'Namibia Standard Time'=>'Africa/Windhoek',
+        'Nepal Standard Time'=>'Asia/Katmandu',
+        'New Zealand Standard Time'=>'Pacific/Auckland',
+        'Newfoundland Standard Time'=>'America/St_Johns',
+        'North Asia East Standard Time'=>'Asia/Irkutsk',
+        'North Asia Standard Time'=>'Asia/Krasnoyarsk',
+        'Pacific SA Standard Time'=>'America/Santiago',
+        'Pacific Standard Time'=>'America/Los_Angeles',
+        'Pacific Standard Time (Mexico)'=>'America/Santa_Isabel',
+        'Pakistan Standard Time'=>'Asia/Karachi',
+        'Paraguay Standard Time'=>'America/Asuncion',
+        'Romance Standard Time'=>'Europe/Paris',
+        'Russian Standard Time'=>'Europe/Moscow',
+        'SA Eastern Standard Time'=>'America/Cayenne',
+        'SA Pacific Standard Time'=>'America/Bogota',
+        'SA Western Standard Time'=>'America/La_Paz',
+        'SE Asia Standard Time'=>'Asia/Bangkok',
+        'Samoa Standard Time'=>'Pacific/Apia',
+        'Singapore Standard Time'=>'Asia/Singapore',
+        'South Africa Standard Time'=>'Africa/Johannesburg',
+        'Sri Lanka Standard Time'=>'Asia/Colombo',
+        'Syria Standard Time'=>'Asia/Damascus',
+        'Taipei Standard Time'=>'Asia/Taipei',
+        'Tasmania Standard Time'=>'Australia/Hobart',
+        'Tokyo Standard Time'=>'Asia/Tokyo',
+        'Tonga Standard Time'=>'Pacific/Tongatapu',
+        'US Eastern Standard Time'=>'America/Indianapolis',
+        'US Mountain Standard Time'=>'America/Phoenix',
+        'UTC+12'=>'Etc/GMT-12',
+        'UTC-02'=>'Etc/GMT+2',
+        'UTC-11'=>'Etc/GMT+11',
+        'Ulaanbaatar Standard Time'=>'Asia/Ulaanbaatar',
+        'Venezuela Standard Time'=>'America/Caracas',
+        'Vladivostok Standard Time'=>'Asia/Vladivostok',
+        'W. Australia Standard Time'=>'Australia/Perth',
+        'W. Central Africa Standard Time'=>'Africa/Lagos',
+        'W. Europe Standard Time'=>'Europe/Berlin',
+        'West Asia Standard Time'=>'Asia/Tashkent',
+        'West Pacific Standard Time'=>'Pacific/Port_Moresby',
+        'Yakutsk Standard Time'=>'Asia/Yakutsk',
+
+        // Microsoft exchange timezones
+        // Source:
+        // http://msdn.microsoft.com/en-us/library/ms988620%28v=exchg.65%29.aspx
+        //
+        // Correct timezones deduced with help from:
+        // http://en.wikipedia.org/wiki/List_of_tz_database_time_zones
+        'Universal Coordinated Time' => 'UTC',
+        'Casablanca, Monrovia' => 'Africa/Casablanca',
+        'Greenwich Mean Time: Dublin, Edinburgh, Lisbon, London' => 'Europe/Lisbon',
+        'Greenwich Mean Time; Dublin, Edinburgh, London' =>  'Europe/London',
+        'Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna' => 'Europe/Berlin',
+        'Belgrade, Pozsony, Budapest, Ljubljana, Prague' => 'Europe/Prague',
+        'Brussels, Copenhagen, Madrid, Paris' => 'Europe/Paris',
+        'Paris, Madrid, Brussels, Copenhagen' => 'Europe/Paris',
+        'Prague, Central Europe' => 'Europe/Prague',
+        'Sarajevo, Skopje, Sofija, Vilnius, Warsaw, Zagreb' => 'Europe/Sarajevo',
+        'West Central Africa' => 'Africa/Luanda', // This was a best guess
+        'Athens, Istanbul, Minsk' => 'Europe/Athens',
+        'Bucharest' => 'Europe/Bucharest',
+        'Cairo' => 'Africa/Cairo',
+        'Harare, Pretoria' => 'Africa/Harare',
+        'Helsinki, Riga, Tallinn' => 'Europe/Helsinki',
+        'Israel, Jerusalem Standard Time' => 'Asia/Jerusalem',
+        'Baghdad' => 'Asia/Baghdad',
+        'Arab, Kuwait, Riyadh' => 'Asia/Kuwait',
+        'Moscow, St. Petersburg, Volgograd' => 'Europe/Moscow',
+        'East Africa, Nairobi' => 'Africa/Nairobi',
+        'Tehran' => 'Asia/Tehran',
+        'Abu Dhabi, Muscat' => 'Asia/Muscat', // Best guess
+        'Baku, Tbilisi, Yerevan' => 'Asia/Baku',
+        'Kabul' => 'Asia/Kabul',
+        'Ekaterinburg' => 'Asia/Yekaterinburg',
+        'Islamabad, Karachi, Tashkent' => 'Asia/Karachi',
+        'Kolkata, Chennai, Mumbai, New Delhi, India Standard Time' => 'Asia/Calcutta',
+        'Kathmandu, Nepal' => 'Asia/Kathmandu',
+        'Almaty, Novosibirsk, North Central Asia' => 'Asia/Almaty',
+        'Astana, Dhaka' => 'Asia/Dhaka',
+        'Sri Jayawardenepura, Sri Lanka' => 'Asia/Colombo',
+        'Rangoon' => 'Asia/Rangoon',
+        'Bangkok, Hanoi, Jakarta' => 'Asia/Bangkok',
+        'Krasnoyarsk' => 'Asia/Krasnoyarsk',
+        'Beijing, Chongqing, Hong Kong SAR, Urumqi' => 'Asia/Shanghai',
+        'Irkutsk, Ulaan Bataar' => 'Asia/Irkutsk',
+        'Kuala Lumpur, Singapore' => 'Asia/Singapore',
+        'Perth, Western Australia' => 'Australia/Perth',
+        'Taipei' => 'Asia/Taipei',
+        'Osaka, Sapporo, Tokyo' => 'Asia/Tokyo',
+        'Seoul, Korea Standard time' => 'Asia/Seoul',
+        'Yakutsk' => 'Asia/Yakutsk',
+        'Adelaide, Central Australia' => 'Australia/Adelaide',
+        'Darwin' => 'Australia/Darwin',
+        'Brisbane, East Australia' => 'Australia/Brisbane',
+        'Canberra, Melbourne, Sydney, Hobart (year 2000 only)' => 'Australia/Sydney',
+        'Guam, Port Moresby' => 'Pacific/Guam',
+        'Hobart, Tasmania' => 'Australia/Hobart',
+        'Vladivostok' => 'Asia/Vladivostok',
+        'Magadan, Solomon Is., New Caledonia' => 'Asia/Magadan',
+        'Auckland, Wellington' => 'Pacific/Auckland',
+        'Fiji Islands, Kamchatka, Marshall Is.' => 'Pacific/Fiji',
+        'Nuku\'alofa, Tonga' => 'Pacific/Tongatapu',
+        'Azores' => 'Atlantic/Azores',
+        'Cape Verde Is.' => 'Atlantic/Cape_Verde',
+        'Mid-Atlantic' => 'America/Noronha',
+        'Brasilia' => 'America/Sao_Paulo', // Best guess
+        'Buenos Aires' => 'America/Argentina/Buenos_Aires',
+        'Greenland' => 'America/Godthab',
+        'Newfoundland' => 'America/St_Johns',
+        'Atlantic Time (Canada)' => 'America/Halifax',
+        'Caracas, La Paz' => 'America/Caracas',
+        'Santiago' => 'America/Santiago',
+        'Bogota, Lima, Quito' => 'America/Bogota',
+        'Eastern Time (US & Canada)' => 'America/New_York',
+        'Indiana (East)' => 'America/Indiana/Indianapolis',
+        'Central America' => 'America/Guatemala',
+        'Central Time (US & Canada)' => 'America/Chicago',
+        'Mexico City, Tegucigalpa' => 'America/Mexico_City',
+        'Saskatchewan' => 'America/Edmonton',
+        'Arizona' => 'America/Phoenix',
+        'Mountain Time (US & Canada)' => 'America/Denver', // Best guess
+        'Pacific Time (US & Canada); Tijuana' => 'America/Los_Angeles', // Best guess
+        'Alaska' => 'America/Anchorage',
+        'Hawaii' => 'Pacific/Honolulu',
+        'Midway Island, Samoa' => 'Pacific/Midway',
+        'Eniwetok, Kwajalein, Dateline Time' => 'Pacific/Kwajalein',
+
+        // The following list are timezone names that could be generated by
+        // Lotus / Domino
+        'Dateline'               => 'Etc/GMT-12',
+        'Samoa'                  => 'Pacific/Apia',
+        'Hawaiian'               => 'Pacific/Honolulu',
+        'Alaskan'                => 'America/Anchorage',
+        'Pacific'                => 'America/Los_Angeles',
+        'Pacific Standard Time'  => 'America/Los_Angeles',
+        'Mexico Standard Time 2' => 'America/Chihuahua',
+        'Mountain'               => 'America/Denver',
+        'Mountain Standard Time' => 'America/Chihuahua',
+        'US Mountain'            => 'America/Phoenix',
+        'Canada Central'         => 'America/Edmonton',
+        'Central America'        => 'America/Guatemala',
+        'Central'                => 'America/Chicago',
+        'Central Standard Time'  => 'America/Mexico_City',
+        'Mexico'                 => 'America/Mexico_City',
+        'Eastern'                => 'America/New_York',
+        'SA Pacific'             => 'America/Bogota',
+        'US Eastern'             => 'America/Indiana/Indianapolis',
+        'Venezuela'              => 'America/Caracas',
+        'Atlantic'               => 'America/Halifax',
+        'Central Brazilian'      => 'America/Manaus',
+        'Pacific SA'             => 'America/Santiago',
+        'SA Western'             => 'America/La_Paz',
+        'Newfoundland'           => 'America/St_Johns',
+        'Argentina'              => 'America/Argentina/Buenos_Aires',
+        'E. South America'       => 'America/Belem',
+        'Greenland'              => 'America/Godthab',
+        'Montevideo'             => 'America/Montevideo',
+        'SA Eastern'             => 'America/Belem',
+        'Mid-Atlantic'           => 'Etc/GMT-2',
+        'Azores'                 => 'Atlantic/Azores',
+        'Cape Verde'             => 'Atlantic/Cape_Verde',
+        'Greenwich'              => 'Atlantic/Reykjavik', // No I'm serious.. Greenwich is not GMT.
+        'Morocco'                => 'Africa/Casablanca',
+        'Central Europe'         => 'Europe/Prague',
+        'Central European'       => 'Europe/Sarajevo',
+        'Romance'                => 'Europe/Paris',
+        'W. Central Africa'      => 'Africa/Lagos', // Best guess
+        'W. Europe'              => 'Europe/Amsterdam',
+        'E. Europe'              => 'Europe/Minsk',
+        'Egypt'                  => 'Africa/Cairo',
+        'FLE'                    => 'Europe/Helsinki',
+        'GTB'                    => 'Europe/Athens',
+        'Israel'                 => 'Asia/Jerusalem',
+        'Jordan'                 => 'Asia/Amman',
+        'Middle East'            => 'Asia/Beirut',
+        'Namibia'                => 'Africa/Windhoek',
+        'South Africa'           => 'Africa/Harare',
+        'Arab'                   => 'Asia/Kuwait',
+        'Arabic'                 => 'Asia/Baghdad',
+        'E. Africa'              => 'Africa/Nairobi',
+        'Georgian'               => 'Asia/Tbilisi',
+        'Russian'                => 'Europe/Moscow',
+        'Iran'                   => 'Asia/Tehran',
+        'Arabian'                => 'Asia/Muscat',
+        'Armenian'               => 'Asia/Yerevan',
+        'Azerbijan'              => 'Asia/Baku',
+        'Caucasus'               => 'Asia/Yerevan',
+        'Mauritius'              => 'Indian/Mauritius',
+        'Afghanistan'            => 'Asia/Kabul',
+        'Ekaterinburg'           => 'Asia/Yekaterinburg',
+        'Pakistan'               => 'Asia/Karachi',
+        'West Asia'              => 'Asia/Tashkent',
+        'India'                  => 'Asia/Calcutta',
+        'Sri Lanka'              => 'Asia/Colombo',
+        'Nepal'                  => 'Asia/Kathmandu',
+        'Central Asia'           => 'Asia/Dhaka',
+        'N. Central Asia'        => 'Asia/Almaty',
+        'Myanmar'                => 'Asia/Rangoon',
+        'North Asia'             => 'Asia/Krasnoyarsk',
+        'SE Asia'                => 'Asia/Bangkok',
+        'China'                  => 'Asia/Shanghai',
+        'North Asia East'        => 'Asia/Irkutsk',
+        'Singapore'              => 'Asia/Singapore',
+        'Taipei'                 => 'Asia/Taipei',
+        'W. Australia'           => 'Australia/Perth',
+        'Korea'                  => 'Asia/Seoul',
+        'Tokyo'                  => 'Asia/Tokyo',
+        'Yakutsk'                => 'Asia/Yakutsk',
+        'AUS Central'            => 'Australia/Darwin',
+        'Cen. Australia'         => 'Australia/Adelaide',
+        'AUS Eastern'            => 'Australia/Sydney',
+        'E. Australia'           => 'Australia/Brisbane',
+        'Tasmania'               => 'Australia/Hobart',
+        'Vladivostok'            => 'Asia/Vladivostok',
+        'West Pacific'           => 'Pacific/Guam',
+        'Central Pacific'        => 'Asia/Magadan',
+        'Fiji'                   => 'Pacific/Fiji',
+        'New Zealand'            => 'Pacific/Auckland',
+        'Tonga'                  => 'Pacific/Tongatapu',
+    );
+
+    /**
+     * List of microsoft exchange timezone ids.
+     *
+     * Source: http://msdn.microsoft.com/en-us/library/aa563018(loband).aspx
+     */
+    public static $microsoftExchangeMap = array(
+        0  => 'UTC',
+        31 => 'Africa/Casablanca',
+
+        // Insanely, id #2 is used for both Europe/Lisbon, and Europe/Sarajevo.
+        // I'm not even kidding.. We handle this special case in the
+        // getTimeZone method.
+        2  => 'Europe/Lisbon',
+        1  => 'Europe/London',
+        4  => 'Europe/Berlin',
+        6  => 'Europe/Prague',
+        3  => 'Europe/Paris',
+        69 => 'Africa/Luanda', // This was a best guess
+        7  => 'Europe/Athens',
+        5  => 'Europe/Bucharest',
+        49 => 'Africa/Cairo',
+        50 => 'Africa/Harare',
+        59 => 'Europe/Helsinki',
+        27 => 'Asia/Jerusalem',
+        26 => 'Asia/Baghdad',
+        74 => 'Asia/Kuwait',
+        51 => 'Europe/Moscow',
+        56 => 'Africa/Nairobi',
+        25 => 'Asia/Tehran',
+        24 => 'Asia/Muscat', // Best guess
+        54 => 'Asia/Baku',
+        48 => 'Asia/Kabul',
+        58 => 'Asia/Yekaterinburg',
+        47 => 'Asia/Karachi',
+        23 => 'Asia/Calcutta',
+        62 => 'Asia/Kathmandu',
+        46 => 'Asia/Almaty',
+        71 => 'Asia/Dhaka',
+        66 => 'Asia/Colombo',
+        61 => 'Asia/Rangoon',
+        22 => 'Asia/Bangkok',
+        64 => 'Asia/Krasnoyarsk',
+        45 => 'Asia/Shanghai',
+        63 => 'Asia/Irkutsk',
+        21 => 'Asia/Singapore',
+        73 => 'Australia/Perth',
+        75 => 'Asia/Taipei',
+        20 => 'Asia/Tokyo',
+        72 => 'Asia/Seoul',
+        70 => 'Asia/Yakutsk',
+        19 => 'Australia/Adelaide',
+        44 => 'Australia/Darwin',
+        18 => 'Australia/Brisbane',
+        76 => 'Australia/Sydney',
+        43 => 'Pacific/Guam',
+        42 => 'Australia/Hobart',
+        68 => 'Asia/Vladivostok',
+        41 => 'Asia/Magadan',
+        17 => 'Pacific/Auckland',
+        40 => 'Pacific/Fiji',
+        67 => 'Pacific/Tongatapu',
+        29 => 'Atlantic/Azores',
+        53 => 'Atlantic/Cape_Verde',
+        30 => 'America/Noronha',
+         8 => 'America/Sao_Paulo', // Best guess
+        32 => 'America/Argentina/Buenos_Aires',
+        60 => 'America/Godthab',
+        28 => 'America/St_Johns',
+         9 => 'America/Halifax',
+        33 => 'America/Caracas',
+        65 => 'America/Santiago',
+        35 => 'America/Bogota',
+        10 => 'America/New_York',
+        34 => 'America/Indiana/Indianapolis',
+        55 => 'America/Guatemala',
+        11 => 'America/Chicago',
+        37 => 'America/Mexico_City',
+        36 => 'America/Edmonton',
+        38 => 'America/Phoenix',
+        12 => 'America/Denver', // Best guess
+        13 => 'America/Los_Angeles', // Best guess
+        14 => 'America/Anchorage',
+        15 => 'Pacific/Honolulu',
+        16 => 'Pacific/Midway',
+        39 => 'Pacific/Kwajalein',
+    );
+
+    /**
+     * This method will try to find out the correct timezone for an iCalendar
+     * date-time value.
+     *
+     * You must pass the contents of the TZID parameter, as well as the full
+     * calendar.
+     *
+     * If the lookup fails, this method will return the default PHP timezone
+     * (as configured using date_default_timezone_set, or the date.timezone ini
+     * setting).
+     *
+     * Alternatively, if $failIfUncertain is set to true, it will throw an
+     * exception if we cannot accurately determine the timezone.
+     *
+     * @param string $tzid
+     * @param OldSabre\VObject\Component $vcalendar
+     * @return DateTimeZone
+     */
+    static public function getTimeZone($tzid, Component $vcalendar = null, $failIfUncertain = false) {
+
+        // First we will just see if the tzid is a support timezone identifier.
+        try {
+            return new \DateTimeZone($tzid);
+        } catch (\Exception $e) {
+        }
+
+        // Next, we check if the tzid is somewhere in our tzid map.
+        if (isset(self::$map[$tzid])) {
+            return new \DateTimeZone(self::$map[$tzid]);
+        }
+
+        // Maybe the author was hyper-lazy and just included an offset. We
+        // support it, but we aren't happy about it.
+        if (preg_match('/^GMT(\+|-)([0-9]{4})$/', $tzid, $matches)) {
+            return new \DateTimeZone('Etc/GMT' . $matches[1] . ltrim(substr($matches[2],0,2),'0'));
+        }
+
+        if ($vcalendar) {
+
+            // If that didn't work, we will scan VTIMEZONE objects
+            foreach($vcalendar->select('VTIMEZONE') as $vtimezone) {
+
+                if ((string)$vtimezone->TZID === $tzid) {
+
+                    // Some clients add 'X-LIC-LOCATION' with the olson name.
+                    if (isset($vtimezone->{'X-LIC-LOCATION'})) {
+
+                        $lic = (string)$vtimezone->{'X-LIC-LOCATION'};
+
+                        // Libical generators may specify strings like
+                        // "SystemV/EST5EDT". For those we must remove the
+                        // SystemV part.
+                        if (substr($lic,0,8)==='SystemV/') {
+                            $lic = substr($lic,8);
+                        }
+
+                        try {
+                            return new \DateTimeZone($lic);
+                        } catch (\Exception $e) {
+                        }
+
+                    }
+                    // Microsoft may add a magic number, which we also have an
+                    // answer for.
+                    if (isset($vtimezone->{'X-MICROSOFT-CDO-TZID'})) {
+                        $cdoId = (int)$vtimezone->{'X-MICROSOFT-CDO-TZID'}->value;
+
+                        // 2 can mean both Europe/Lisbon and Europe/Sarajevo.
+                        if ($cdoId===2 && strpos((string)$vtimezone->TZID, 'Sarajevo')!==false) {
+                            return new \DateTimeZone('Europe/Sarajevo');
+                        }
+
+                        if (isset(self::$microsoftExchangeMap[$cdoId])) {
+                            return new \DateTimeZone(self::$microsoftExchangeMap[$cdoId]);
+                        }
+                    }
+
+                }
+
+            }
+
+        }
+
+        if ($failIfUncertain) {
+            throw new \InvalidArgumentException('We were unable to determine the correct PHP timezone for tzid: ' . $tzid);
+        }
+
+        // If we got all the way here, we default to UTC.
+        return new \DateTimeZone(date_default_timezone_get());
+
+    }
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Version.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Version.php
new file mode 100644
index 0000000..8de8885
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/Version.php
@@ -0,0 +1,24 @@
+<?php
+
+namespace OldSabre\VObject;
+
+/**
+ * This class contains the version number for the VObject package
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+class Version {
+
+    /**
+     * Full version number
+     */
+    const VERSION = '2.1.0';
+
+    /**
+     * Stability : alpha, beta, stable
+     */
+    const STABILITY = 'stable';
+
+}
diff --git a/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/includes.php b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/includes.php
new file mode 100644
index 0000000..d15329a
--- /dev/null
+++ b/calendar/lib/SabreDAV/vendor/oldsabre/vobject/lib/Sabre/VObject/includes.php
@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * Includes file
+ *
+ * This file includes the entire VObject library in one go.
+ * The benefit is that an autoloader is not needed, which is often faster.
+ *
+ * @copyright Copyright (C) 2007-2013 fruux GmbH (https://fruux.com/).
+ * @author Evert Pot (http://evertpot.com/)
+ * @license http://code.google.com/p/sabredav/wiki/License Modified BSD License
+ */
+
+// Begin includes
+include __DIR__ . '/DateTimeParser.php';
+include __DIR__ . '/ElementList.php';
+include __DIR__ . '/FreeBusyGenerator.php';
+include __DIR__ . '/Node.php';
+include __DIR__ . '/Parameter.php';
+include __DIR__ . '/ParseException.php';
+include __DIR__ . '/Property.php';
+include __DIR__ . '/Reader.php';
+include __DIR__ . '/RecurrenceIterator.php';
+include __DIR__ . '/Splitter/SplitterInterface.php';
+include __DIR__ . '/StringUtil.php';
+include __DIR__ . '/TimeZoneUtil.php';
+include __DIR__ . '/Version.php';
+include __DIR__ . '/Splitter/VCard.php';
+include __DIR__ . '/Component.php';
+include __DIR__ . '/Document.php';
+include __DIR__ . '/Property/Compound.php';
+include __DIR__ . '/Property/DateTime.php';
+include __DIR__ . '/Property/MultiDateTime.php';
+include __DIR__ . '/Splitter/ICalendar.php';
+include __DIR__ . '/Component/VAlarm.php';
+include __DIR__ . '/Component/VCalendar.php';
+include __DIR__ . '/Component/VEvent.php';
+include __DIR__ . '/Component/VFreeBusy.php';
+include __DIR__ . '/Component/VJournal.php';
+include __DIR__ . '/Component/VTodo.php';
+// End includes