Maximum OpenGL version

[Fabian Maurer]

Currently looking at the directx11 implementation, and I noticed I first need 
to set a "MaxVersionGL" in the registry to enable creation of 4.3 context and 
so DX11 support.
What's the reason behind this?

The change is from a1e718ccabc7c330dd16c7face78022965b03e20 (wined3d: Add a 
setting for the maximum OpenGL version to use).
Why do we need to set the maximum version instead of just using the highest 
context we can get (and still use) ?

Fabian Maurer