- Update the SCHEDULE-STATUS parameter correctly when writing the event
to the organiser.
- Don't include ETag in PUT response when scheduling actions occur.
- Write scheduling resources to attendee calendars even when this is
an event modification.
In the new Scheduling Extensions for CalDAV the server is expected
to construct iCalendar METHOD:REQUEST invitations and put them into
the scheduling inbox for each (local) attendee. This patch does
that, and hopefully breaks the back of implementing the full
scheduling extensions.
