Yasm r1713 fixed; building and Windows-native

[Neil Mitchell]

Hi

> As a general procedure, I would personally rather solve all Windows-
> compatibility problems first, then redo the build system to use SCons
> or some other Windows-native system and go from there.

Yhc uses Scons. I personally don't recommend it.

Makefiles are obviously absolutely horrible on Windows.

CMake is next on my list of "build systems to try"

Thanks

Neil