* Created MockProvider that can be used for testing the results of
ContentProviderOperation's for Calendar/Contacts (we can't use these
within our mock contexts because we can't instantiate the provider
classes within the Email package)
* Wrote some unit tests for MockProvider
* Use MockProvider to test addEvent, in particular how a user's attendee
status is stored, depending on whether the event is new or updated
Change-Id: I97f02d125eb7347726261e12ce70aadc539be1d4
f115d31ae8