* Added initial version of JIT accelerated yuv420p -> yuyv422
    scaler (Nokia 770 only). This scaler is a lot faster (up to
    8x factor) than any of the standard scalers from libswscale
    (the previous implementation). Right now image quality for
    scaled video decreased somewhat, but that will be fixed in
    one of the next versions. In order to revert to old scaler
    implementation you can use '-vo nokia770:jitscale=0' command
    line option. Also 'jitscale' suboption sets image quality
    for JIT scaler. Right now there are two settings: 2 (default)
    and 1 (a bit faster but looks even worse - that's nearest
    neighbour / point scaler algorithm). This new fast scaler
    eliminates an old weakness of maemo port of MPlayer - jerky
    playback for 'inconvenient' video resolutions.
  * Some optimizations for unscaled yuv420p -> yuyv422 color format
    conversion (up to 1.5x improvement)
  * Added 'vo_change_rectangle' slave command, it can be used to
    change video output screen area any time, this command
    works with -vo nokia770 video output driver