split out development content to https://pypa.io

this removes the development content, so it can live on https://pypa.io
built html:  http://python-packaging-user-guide.readthedocs.org/en/pypa.io/

The PR for pypa.io:  https://github.com/pypa/pypa.io/pull/1
built html:  http://pypaio.readthedocs.org/en/initial/