Blender Git Loki

Fix T51721: OpenGL Detection is broken on Windows

Now computers that support OpenGl3.3 (but not 4.5) can run Blender 2.8.

For any given HDC, you may only call SetPixelFormat *ONCE* any future
calls for the same HDC will fail. And computers that would support only
OpenGL 3.3 wouldn't have a change to get a valid OpenGL context because
the pixelformat was already set while trying to probe the supported
contexts.

We fix this by splitting the final context creation from the query of
supported OpenGL versions.

Patch by Ray Molenkamp (bzzt_ploink/LazyDodo) with code style fixes and
comments by me.