request single buffered context on windows

Change-Id: I7b9789053872446e312ae4e3c471986e3c5c55d2
windows opengl: Set PFD_DOUBLEBUFFER even for single buffer rendering.

Otherwise I'm getting lots of errers when dealing with virtual devices...

Change-Id: I34e145817d21dfc2d30fa9ffdfedfa714467d105