Added python3 support and fixed Windows compatiblity.

I tested this on Windows 7 ultiamte 32bit.

Doesn't work on ubuntu 14. It seems to have something to do with new chages in 14.
I don't think you need full six. See https://github.com/feross/SpoofMAC/pull/26. According to 2to3 anyway, this is the only issue, which is easily fixed with a try, except ImportError.