Initial interface/hooks for GE debugger

Could get really complicated... but also very useful.

Initial notes on possible functionality / user interface:
https://github.com/unknownbrackets/ppsspp/wiki/GE-Debugger

Doesn't really do anything useful yet except break/resume execution and logs the opcode on break, but it's initial groundwork.  Made a token effort at least to try to keep Qt from breaking.

-[Unknown]