overhaul snes core -- radically simplify IPC.
There were two goals
1. speedup (failed)
2. not break in the old way of becoming unstable when GC happens (uncertain)
3. lay framework for simplified libretro interface (success, provisional on #2)
the speedup failed, I think, because a slower libco is needed to coexist with .net. I think I will fix this be incorporating both libcos, one for bsnes internal use, and one for .net<->c++ switching
alyosha-tas