Log information about GPU used by OpenGL on startup.
Auto-select nVidia GPU on Optimus laptops.

Since we're no longer using DirectX, nVidia's automatic detection no longer works classifies OpenClonk as a game to use the high performance GPU. Note that this flag does not work on some old drivers (version<302 according to specs). To support these old drivers, we would have to link against DirectX despite not using it.
Fix Win32 MinGW build.

I hope...