Generate wheels for windows instead of (or in addition to, I guess) EXE files.

[dougthor42]

Wheels would provide the best support for all users - Windows, Mac, and Linux.

I see that you have Appveyor running unit tests - I'll see if I can get wheels made there too.

[Scondo]

EXE made to provide speed-up done with Cython for Windows users. Linux users most often have C compiler and can handle pngfilters.c in tar.gz distribution.

tar.gz also used by pip on any platform for provide pure-python mode.

So Windows-only binary wheels may provide slightly better compatibility with pip on Windows, but I doubt for more...