[wined3d] GetFrontBufferData

[Karsten Elfenbein]

Hi,

this is the patch that allows EVE online to capture ingame screenshots.
(fixes the start coordinates for glReadPixels and turns the output
upside down again)
It works with the login screen (running as managed window) and in
fullscreen. (when desktop is 32bit)
Is there much more stuff needed or would cleaning up the code and
replacing the 4 with the size of a pixel do the trick for the tree?

Karsten