Remove deprecated unused opengl functions
merge OGLExtRender with OGLRender class. Potentially create some memory leak as the constructor and destructor are empty.
Remove Force fog option (this option actually break a lot of stuff and make most games unplayables Remove OGLRender::SetFogEnable as it now do the exact same thing than CRender::SetFogEnable and so, it useless
Remove SetFogMinMax function from CRender as it's useless, Color Combiner now directly use the RDP state