New graphics API and Windows installer for pySFML

I added support for pySFML's new graphics API a while ago, and I recently added a Windows installer (that's the .exe file, the .zip are older releases). There's no Python 3 installer currently, because Visual Studio fails to compile it. I'll see if I can fix it, or use MinGW instead.

If you're using Python 2 and are interested in multimedia/2D development, try it out! But please keep in mind that it's not a stable release yet and that bug reports and suggestions are very helpful.

Update: Python 3 installers are now available.