The interface looked like a good idea around the time Clutter 0.2 was
out, but in reality we never had a proper, and supported implementation
outside of clutter-gst - thus, ClutterMedia was acting like a wrapper
around GStreamer, leading to hilarious issues of impedence mismatch
between API and all sorts of indirection issues typical of wrong
abstractions.
In theory, ClutterMedia should have been deprecated and removed before
we hit 1.0, but we kept flip-flopping on the issue.
For 2.0, it's time to take it out.
And shoot it in the face.
