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 00fe5057f13bca3416b9d25a1fe9df27c514b29c, 74b5fb3ab4b066681336d1be44c7eecfcf6a4dc6, cd46138d299088631bbcbf37543584946c4b174a and 5f72542e0637799092ad1006d16ebad1961020e0 because taking screenshots in D3D still crashed for me so there was no point in the code changes (which I found ugly anyway).
D3D doesn't allow bigger viewports than rendertargets. But flipper does, so the viewport will be clipped and the transformation matrix will be changed.
This was done in the D3D backend itself. This is now moved into VideoCommon. This don't reduce code, but in this way, VideoCommon doesn't depend on the backends.
