Build environment for official win32 builds

[Tor Lillqvist]

> Okay, but this cant explain why cygwin/gcc is so horribly slow
> compared to msvc (would make both of them slow).

Cygwin is a POSIX emulation. Some POSIX concepts are *very* different
from Windows. Emulating them takes time and effort.

> autoconf alone already is evil enough ;-)

Feel free to waste your time coming up with an equivalent alternative.

--tml