• The zip release ships with sabre/vobject 3.2.2,
  sabre/http 2.0.3, and sabre/event 1.0.0.
• BC Break: Property updating and fetching got refactored. Read the migration
  document for more information. This allows for creation of a generic
  property storage, and other property-related functionality that was not
  possible before.
• BC Break: Removed propertyUpdate, beforeGetProperties and
  afterGetProperties events.
• Fixed: #413: Memory optimizations for the CardDAV PDO backend.
• Updated: Brand new browser plugin with more debugging features and a design
  that is slightly less painful.
• Added: Support for the {DAV:}supported-method-set property server-wide.
• Making it easier for implementors to override how the CardDAV addressbook
  home is located.
• Fixed: Issue #422 Preconditions were not being set on PUT on non-existant
  files. Not really a chance for data-loss, but incorrect nevertheless.
• Fixed: Issue #428: Etag check with If: fails if the target is a collection.
• Fixed: Issues #430, #431, #433: Locks plugin didn't not properly release
  filesystem based locks.
• Fixed: #443. Support for creating new calendar subscriptions for OS X 10.9.2
  and up.
• Removed: Sabre\DAV\Server::NODE_* constants.
• Moved all precondition checking into a central place, instead of having to
  think about it on a per-method basis.
• jCal transformation for calendar-query REPORT now works again.
• Switched to PSR-4
• Fixed: #175. Returning ETag header upon a failed If-Match or
  If-None-Match check.
• Removed: lib/Sabre/autoload.php. Use vendor/autoload.php instead.
• Removed: all the rfc documentation from the sabre/dav source. This made the
  package needlessly larger.
• Updated: Issue #439. Lots of updates in PATCH support. The
  Sabre_DAV_PartialUpdate_IFile interface is now deprecated and will be
  removed in a future version.
• Added: Sabre\DAV\Exception\LengthRequired.