Clean up the mess that is CalObjModType.

Clean up the mess that is CalObjModType.

Deprecate both CalObjModType and EDataCalObjModType.

Introduce ECalObjModType with equivalent but properly namespaced enum
values, generate a GType for this enum, and swap out CalObjModType for
ECalObjModType throughout the calendar API.

Trying not to break the API here, but this is a freakin mess.