Switch to lossless compression for AVI

[vadosnaprimer]

For years mame has beed recording AVI with audio and video uncompressed. Code-wise, it is sane to use the screenshot buffer and just dump it to video file, but for a user, it feels dirty and generates an overly huge file, let alone the fact that every major emulator out there has some way of compressing the video it records (lack of audio compression doesn't give so much overhead, so everybody still uses uncompressed wav).

There are various ways to solve this.

• The first one, that's now considered too old and ugly (and Windows only), is using VideoForWindows, that gives you the list of codecs it could use. Implemented in FCEUX, Desmume, snes9x.
• The second one is using a built-in codec, like ZMBV or GZip. It is better, because it's fully portable and equally stable for all platforms. Emulators that use it: DOSBox, openMSX, lsnes, Mesen (since the latest commit).
• The third option is embedding an ffmpeg recorder. This requires some tricks to get it to work when one is encoding the recorded video, but is also cross-platform and feature-rich. Emulators that use it: Dolphin, PPSSPP.