Fix for hotkeys ctr-shift-alt F1/F2 xbmc in fullscreen.
Removed try/except, using subprocess.call instead of os.system. Write message to stderr. Added sys.exit with return codes, no problems with xbmc when doing that.
Corrected mistake, check if keyboard.xml exist.
Merge pull request #1241 from divx118/xbmc-hotkey

Fix for hotkeys ctr-shift-alt F1/F2 xbmc in fullscreen.