CPPageExternalFilters: fix wrong popup point check

Casting UINT to int and then comparing it to 0 is just wrong
Profile: fix inability to open locked mpc-hc.ini

I previously misjudged c++ semantics pretty badly here
Shaders: rename resources to be presentable
Shaders: add license headers to resources
Shaders: cosmetics in resources
Shaders: new dialog
Shaders: massive clean up
Shaders: adjust behavior