Goal: Synchronize calendars on two computers running Evolution by syncing both to a common (network-mounted) folder.

Steps to reproduce:
1.  Sync computer A to network folder (successful)
2.  Sync computer B to network folder (EvoCalendar --> folder succeeds, folder --> EvoCalendar fails)

Root cause:
EvoCalendar's _get_object returns an iCal VCALENDAR containing a single VEVENT for each event on the calendar.  However, EvoCalendar's _create_object expects an iCal VEVENT.  The evolution-data-server can't parse the VCALENDAR and fails.

Suggested fix:
Modify EvoCalendar's _get_object to return a VEVENT instead of a VCALENDAR.  See attached patch.  

Alternative fix:
In EvoCalendar's _create_object, parse the VEVENT out of the VCALENDAR before calling evolution.ecal.ECalComponent().  I'm not familiar enough with the vobject API to do this quickly.

Other considerations:
The other two consumers for Events (AFAICT) are the Google Calendar and the iPod calendar.  It's not clear to me what format they expect.  I can't test the iPod (lack of hardware) and the Google Calendar module is disabled, assumedly for good reason.