Move ReapplyGfxState() to GPUCommon.

This way it can be overridden, and simplifies some other things.
Add a function to run the CPU core.
Simplify ProcessDLQueue() slightly.
Merge pull request #3057 from unknownbrackets/gpu-thread

Prep work for GE and CPU on separate threads
Win32: Enable user to change emulated PSP nickname from the menu screens by popping a dialog box.
Win32: Enable user to bypass the in-game OSK by using the same dialog box. It doesn't support non-Roman characters yet.
Fix includes.