[FIX] Add back PCSX2 support

[Dnawrkshp]

• Add PCSX2 toggle to switch between PCSX2/RPCS3
• Add InvertX and InvertY axis toggles
• Add UYA PS2 Multiplayer support (addresses courtesy of Eski)

[isJuhn]

I made some changes to SetEmulator to make the toggle consistent and functional after toggling.

Anyway, the only difference between PINE pcsx2 and rpcs3 in our case is the port, so I just changed the port in pcsx2 to make it work there. But it was never a long term solution. I plan on doing auto detection in the future, but I don't spend much time on KAMI anymore. The lifetime of things like the thread and the KeyHandler is unfortunate, maybe I'll clean it up later and make KAMICore disposable.

Check if it still works good for you with my changes and then I'll fix the commit history (hopefully github won't be so confused by the line endings then) and then merge.

[Dnawrkshp]

Everything runs great. Thanks for cleaning it up!