Add script function to trigger a manual rating.

Add a script function to trigger a manual rating from either a keypress association, or from within a skin.
Use, RunScript(script.trakt,action=rate) to trigger a manual rating.
Check the type of media currently selected based on the currently visible container  (movie, tvshow, season, episode).
Signal service thread with type of media and DB id of currently selected item to perform a manual rating.
Add signalling check ins ervice thread for manual rating.
Add season/episode to raiting dialog, now shows <Show> - S##E## - <Episode Title>.