Standard Windows cPython 3.5 64bit compatibility

[stonebig]

It looks like Python 3.5 64bit will be the convergence point for Python 2 and Python 3.

Unfortunately on Windows, the lack of 'easy' cython solution is a handicap to accelerate in that direction.

[carlkl]

see https://mingwpy.github.io/issues.html#the-vs-14-2015-runtime
and winpython/winpython#67 (comment)