Try to atomically save config files.
ShaderGen: remove nonsense for() if() {}
ShaderGen: drop PerPixelLighting + 8Texcoord hack

D3D9 only supports 8 texcoords. But we need a new one for ppl, so we just store it in the first 4 texcoords in the free 4th component.

This isn't needed for both d3d11 and ogl3, so just remove it.
ShaderGen: fix for commit bd80de14f4ca
Fix config file saving on Windows.
(Netplay) Disable record input checkbox while a game is running.

Fixes issue 6734.