* Use expression bodies in Emulation.Cores, and a few other misc cleanups
* remove unused usings in Emulation.Common
* cleanups in Tables_Direct.cs
* some cleanups in nes boards - redundant code
* remove some redundant array initializers in Emulation.Cores
* cleanup AmstradCPC.Controllers
* use object initializers in a lot of places
* nes mappers - remove disch's notes comments in favor of the nesdev wiki link
* cleanup CdtConverter.cs, mostly use of object initializers
* remove redundant .ToString() calls in Emulation.Cores
* using var in Emulation.Cores
* AmstradCPC/ZXSpectrum - simplify some linq, tabs instead of spaces, a few other misc cleanups
* Use null-propagation in Emulation.Cores
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