More fixes

Add checks in episode and movie sync for collection/watched lists not being lists, and abort if they're not.
Fix traktRequest to check for data is None explicitly instead of true/false, since an empty list is still false.
Add show specific functions in traktapi.
Fix episode sync, when removing all episode, just remove the show.
Add sqlDateToUnixDate helper function
Fix movie sync to also pass last_played in seen requests.