Finish development of CompuMate controller

[sa666666]

The current code allows the CompuMate ROMs to run, and you can interact with the built-in modes. The major item left to implement is loading/saving from a simulated cassette, either by reading/writing compatible wave files, or using an intermediate data format that can be converted to wave externally. Ideally, this would allow Stella to load the recently-released CompuMate cassettes.

[thrust26]

Some info here: http://atariage.com/forums/topic/178634-the-compumate-list/page-6#entry3444915