Issues #24 #23: Add enhanced support for External Players

This adds some enhanced support for the external players.  Particularly
* ViMu from GTV Box for Google TV
* MX Player for various android phones.

* ViMu forces direct play of the files, and passes in the Title of the video.
* MX Player forces hardware decoding, title and the returning result code

The later will eventually be used to update the Plex playback position.

Launching and watching a video in an external player now sets the Watched
status of the video as well in plex.