Add software definition for Python and supporting tools

* Python 2.7.5
* setuptools 0.7.7 (for install `pip`)
* pip 1.3
Add software definition for Sphinx and Pygments.

Useful for generation documentation in Omnibus packages. Pygments is
included so Sphinx does syntax highlighting correctly.
Merge pull request #56 from opscode/python-and-sphinx

Add Python and Friends