Quintessential Player 4.51

- fixed Core - many bug fixes, potential crash fixups, code refactoring
- fixed Plug - tagging new encoded MP3 file fixes
- fixed ML - Playlist renaming in playlist manager
- updated Core - Input plugin management: all access by same independant thread
- updated Core - Playlist menu builds from library playlists
- updated Core - Shuffle order now remains intact on play queue changes/adds/deletes
- updated Core - Playback Pruning mode implemented
- updated Core - Playlist renamed to 'Play Queue'
- updated Plug - ReplayGain analyzes on playback, stores in ML
- updated Plug - updated Gracenote Controls to address Playlist and MusicID issues
- updated ML - performance enhancements
- added Core - skin colorization engine