Passed as a compiler define to be sure it is always define before windows.h
is loaded. This means that Godot officially requires Vista API or later, it will
not work on Windows XP or earlier.
Also fix a bogus check for Windows 7 API.
That year should bring the long-awaited OpenGL ES 3.0 compatible renderer
with state-of-the-art rendering techniques tuned to work as low as middle
end handheld devices - without compromising with the possibilities given
for higher end desktop games of course. Great times ahead for the Godot
community and the gamers that will play our games!
