• Fixed: Issue 131: Custom CalDAV backends could break in certain cases.
• Added: The option to override the default tablename all PDO backends use.
  (Issue 60).
• Fixed: Issue 124: 'File' authentication backend now takes realm into
  consideration.
• Fixed: Sabre_DAV_Property_HrefList now properly deserializes. This allows
  users to update the {DAV:}group-member-set property.
• Added: Helper functions for DateTime-values in Sabre_VObject package.
• Added: VObject library can now automatically map iCalendar properties to
  custom classes.