Add MANIFEST.in to build a proper sdist

http://docs.python.org/2/distutils/sourcedist.html#the-manifest-in-template

To build a proper sdist file (so that we can push to a PyPi mirror) we need to make sure we also bundle in the html, css, and js files into our sdist. This needs to be done even if we list our package_data in setup.py.

It would also be nice to have a specific tag in git for the 0.1 version (or perhaps a 0.2 version if you merge this in :) )