Added new Game Client add-ons based on the libretro API
Add Libretro repository for pre-compiled libretro emulators
Added game info tags to XBMC

XBMC can now load information about games images directly from their file. The following types of game images are currently supported: GBA, GB/GBC
Added RetroPlayer, a new player core that enables game clients to have video, audio and input

No game browser exists yet, but games can be launched from the File Manager. Keymap entries can be configured in the <FullscreenGame> tag of any keymap file.
Added RGB565 support.
Add rewind functionality to GameClient.
Add basic seeking (rewind) support.
Use CSingleLock to lock.
Do not SIGFPE if rewind isn't supported.