• Massive calendars and addressbooks should see a big drop in peak memory
  usage.
• Fixed a privilege bug in the availability system.
• #697: Added a "tableName" member to the PropertyStorage PDO backend. (@Frzk).
• #699: PostgreSQL fix for the Locks PDO backend. (@TCKnet)
• Removed the simplefsserver.php example file. It's not simple enough.
• #703: PropPatch in client is not correctly encoded.
• #709: Throw exception when running into empty
  supported-calendar-component-set.
• #711: Don't trigger deserializers for empty elements in {DAV:}prop. This
  fixes issues when using sabre/dav as a client.
• The zip release ships with sabre/vobject 4.0.0-alpha2,
  sabre/http 4.1.0, sabre/event 2.0.2,
  sabre/uri 1.0.1 and sabre/xml 1.2.0.