Make "color-depth" and "resolution" synonyms for "video-color-depth" and "video-resolution", since not all resources are videos.

This makes it simpler to specify image information, like:

    basename=Sintel Trailer
    profile=item
    mime-type=image/jpeg
    protected=false
    converted=true
    resolution=320x150
    uri=http://durian.blender.org/wp-content/uploads/2010/05/sintel_trailer_1080.jpg