optimize CalendarObject.reconcileGroupAttendees() to only call Component.reconcileGroupAttendees() if group has changed
optimize CalendarObject.reconcileGroupAttendees() to only call Component.reconcileGroupAttendees() if group has changed


git-svn-id: 81e381228600e5752b80483efd2b45b26c451ea2@13334 e27351fd-9f3e-4f54-a53b-843176b1656c

trevor/calendarserver,trevor/calendarserver,trevor/calendarserver