Update VideoDecoders to use the new VideoDecoder-interface (for testing)

I've done an update of the VideoDecoders to use the new VideoDecoder interface, right now the state of this pull request is as follows:
* Bink works for EMI, but probably needs some more work for Myst3 (no testing has been done there, and selection of audio-track atleast is known not to work).
* MPEG2 works for the first time ever in EMI (thanks to clone2727)
* SMUSH was largely rewritten on the muxer-side to fit into the new system (based on a combination of the old ResidualVM-code, and clone2727's smushplay).

I'm not at all sure that everything works perfectly, and the SMUSH-code might need a license change to GPLv2, so feel free to test and give me feedback on this.

This pull request also contains an additional patch from clone2727 to the MPEGPS-decoder, that allows EMI-PS2 to play it's video-sound.