Update to python 2.7.8

This is a verbatim copy of homebrew's python formula, without the old
scripts_directory change for pip/distutils, and is **experimental**
Remove homebrew revision from formula

We use `-boxen*` suffixes for the same result, and the revision
causes our bo-janked binary handling to break
Remove the python env script

It's no longer necessary, as homebrew's python is configured to install
scripts to $HOMEBREW_ROOT/bin
Have to fill in content
Merge pull request #28 from boxen/python-2.7.8

Python 2.7.8