• BC Break: Now requires PHP 5.3
• BC Break: Any node that implemented Sabre_DAVACL_IACL must now also implement
  the getSupportedPrivilegeSet method. See website for details.
• BC Break: Moved functions from Sabre_CalDAV_XMLUtil to
  Sabre_VObject_DateTimeParser.
• BC Break: The Sabre_DAVACL_IPrincipalCollection now has two new methods:
  'searchPrincipals' and 'updatePrincipal'.
• BC Break: Sabre_DAV_ILockable is removed and all related per-node locking
  functionality.
• BC Break: Sabre_DAV_Exception_FileNotFound is now deprecated in favor of
  Sabre_DAV_Exception_NotFound. The former will be removed in a later version.
• BC Break: Removed Sabre_CalDAV_ICalendarUtil, use Sabre_VObject instead.
• BC Break: Sabre_CalDAV_Server is now deprecated, check out the documentation
  on how to setup a caldav server with just Sabre_DAV_Server.
• BC Break: Default Principals PDO backend now needs a new field in the
  'principals' table. See the website for details.
• Added: Ability to create new calendars and addressbooks from within the
  browser plugin.
• Added: Browser plugin: icons for various nodes.
• Added: Support for FREEBUSY reports!
• Added: Support for creating principals with admin-level privileges.
• Added: Possibility to let server send out invitation emails on behalf of
  CalDAV client, using Sabre_CalDAV_Schedule_IMip.
• Changed: beforeCreateFile event now passes data argument by reference.
• Changed: The 'propertyMap' property from Sabre_VObject_Reader, must now be
  specified in Sabre_VObject_Property::$classMap.
• Added: Ability for plugins to tell the ACL plugin which principal plugins are
  searchable.
• Added: [DAVACL] Per-node overriding of supported privileges. This allows for
  custom privileges where needed.
• Added: [DAVACL] Public 'principalSearch' method on the DAVACL plugin, which
  allows for easy searching for principals, based on their properties.
• Added: Sabre_VObject_Component::getComponents() to return a list of only
  components and not properties.
• Added: An includes.php file in every sub-package (CalDAV, CardDAV, DAV,
  DAVACL, HTTP, VObject) as an alternative to the autoloader. This often works
  much faster.
• Added: Support for the 'Me card', which allows Addressbook.app users specify
  which vcard is their own.
• Added: Support for updating principal properties in the DAVACL principal
  backends.
• Changed: Major refactoring in the calendar-query REPORT code. Should make
  things more flexible and correct.
• Changed: The calendar-proxy-[read|write] principals will now only appear in
  the tree, if they actually exist in the Principal backend. This should reduce
  some problems people have been having with this.
• Changed: Sabre_VObject_Element_* classes are now renamed to
  Sabre_VObject_Property. Old classes are retained for backwards compatibility,
  but this will be removed in the future.
• Added: Sabre_VObject_FreeBusyGenerator to generate free-busy reports based on
  lists of events.
• Added: Sabre_VObject_RecurrenceIterator to find all the dates and times for
  recurring events.
• Fixed: Issue 97: Correctly handling RRULE for the calendar-query REPORT.
• Fixed: Issue 154: Encoding of VObject parameters with no value was incorrect.
• Added: Support for {DAV:}acl-restrictions property from RFC3744.
• Added: The contentlength for calendar objects can now be supplied by a CalDAV
  backend, allowing for more optimizations.
• Fixed: Much faster implementation of Sabre_DAV_URLUtil::encodePath.
• Fixed: {DAV:}getcontentlength may now be not specified.
• Fixed: Issue 66: Using rawurldecode instead of urldecode to decode paths from
  clients. This means that + will now be treated as a literal rather than a
  space, and this should improve compatibility with the Windows built-in client.
• Added: Sabre_DAV_Exception_PaymentRequired exception, to emit HTTP 402 status
  codes.
• Added: Some mysql unique constraints to example files.
• Fixed: Correctly formatting HTTP dates.
• Fixed: Issue 94: Sending back Last-Modified header for 304 responses.
• Added: Sabre_VObject_Component_VEvent, Sabre_VObject_Component_VJournal,
  Sabre_VObject_Component_VTodo and Sabre_VObject_Component_VCalendar.
• Changed: Properties are now also automatically mapped to their appropriate
  classes, if they are created using the add() or __set() methods.
• Changed: Cloning VObject objects now clones the entire tree, rather than just
  the default shallow copy.
• Added: Support for recurrence expansion in the CALDAV:calendar-multiget and
  CALDAV:calendar-query REPORTS.
• Changed: CalDAV PDO backend now sorts calendars based on the internal
  'calendarorder' field.
• Added: Issue 181: Carddav backends may no optionally not supply the carddata
  in getCards, if etag and size are specified. This may speed up certain
  requests.
• Added: More arguments to beforeWriteContent and beforeCreateFile (see
  WritingPlugins wiki document).
• Added: Hook for iCalendar validation. This allows us to validate iCalendar
  objects when they're uploaded. At the moment we're just validating syntax.
• Added: VObject now support Windows Timezone names correctly (thanks mrpace2).
• Added: If a timezonename could not be detected, we fall back on the default
  PHP timezone.
• Added: Now a Composer package (thanks willdurand).
• Fixed: Support for \N as a newline character in the VObject reader.
• Added: afterWriteContent, afterCreateFile and afterUnbind events.
• Added: Postgresql example files. Not part of the unittests though, so use at
  your own risk.
• Fixed: Issue 182: Removed backticks from sql queries, so it will work with
  Postgres.