Working Qt interface (debuggers broken)

I tried to simplify code of this interface - instead of custom drawing functions in EmuThread, I used unified code from UI/. OpenGL widget is not clickable at the moment. However, adding this functionality shouldn't be a problem.

In the process, debuggers got broken but I think having ability to run games is better than nothing.

I hope mobile Qt platforms were not affected by this commit, please tell me if anything's wrong.