Make this thing build on windows

Other things required that can't go in the repository:

1. A sane environment (64-bit Python 27 is [a bit of a pain](https://stackoverflow.com/q/11267463/102441))
2. An installation of [OpenSSL](http://slproweb.com/products/Win32OpenSSL.html) that matches your python bitness
3. The following sequence of commands before running `pip`

     > set LIB=<path-to-openssl>/lib;%LIB%
     > set INCLUDE=<path-to-openssl>/include;%INCLUDE%

That should probably go in a readme somewhere