At some point we'll probably want to switch to using state objects inside
wined3d, although that would require some changes to the other users of
wined3d as well.

Fixes a bunch of graphic glitches in WildStar on Nvidia.

They should be generally supported by the existing code.
Specific missing format conversions are caught and reported by
D3DXLoadSurfaceFromMemory(), which is called directly or indirectly
from here.