• #566: Another issue related to the migration script, which would cause
  scheduling to not work well for events that were already added before the
  migration.
• #567: Doing freebusy requests on accounts that had 0 calendars would throw
  a E_NOTICE.
• #579: Browser plugin can throw exception for a few resourcetypes that didn't
  have an icon defined.
• The zip release ships with sabre/vobject 3.3.4,
  sabre/http 3.0.4, and sabre/event 2.0.1.