Restructured core.trakt_objects
Added rating_timestamp to TraktMedia, started working on basic rating conflict resolution
Sync manager reference added to sync tasks, 'section' now passed to task handlers.
Changed timestamps to use UTC time, updated SyncStatus to store timestamp of last successful run.
sync.pull rating updates now have basic conflict resolution, sync.pull now returns successful result properly.
sync.pull Base.rate now returns boolean to indicate success
Added titles to sync.pull and sync.push tasks