Revert "Actually, filename really does need to be a parameter because of some random debug thing."
Revert "fix non-HAVE_WX case"
Revert "Handle screenshot saving in RenderBase. Removes dependency on D3DX11 for screenshots (texture dumping is still broken)."
This reverts commits 00fe5057f1, 74b5fb3ab4, cd46138d29 and 5f72542e06 because taking screenshots in D3D still crashed for me so there was no point in the code changes (which I found ugly anyway).