[dx8-21] Viewport fix

[Ann and Jason Edmeades]

FYI With the attached patch on top of the wine cvs tree, a no-cd install
(requires native msvcrt until I fix the 'thiscall' issue) and running 'wine
war3' warcraft 3 now appears to be pretty much right!!! (No more screen
distortion / misplaced faces etc).

Thanks to everyone who has helped get this far, especially Raphael and
Lucho.

Changelog

Make sure the viewport is from the GL (bottom left) not the DirectX (top
left).

Jason