Virtual Env support via virtualenvwrapper

This adds support for virtual environments in python as well as support
for virtualenv wrapper. Support is pretty basic at this point, but
creation and deletion of venvs is supported
Add support for post(de)activate hooks and upgrade

This adds support for postactivate and postdeactivate in
virtualenvwrapper, as well as adding a flag to have pip do an upgrade
(in case you're not pinning your versions in your requirements files).
Also adds a pip_develop module which is meant to be used in conjunction
with a repository & virtualenv. Equivelent to "pip install -e ." or "python
setup.py develop"
Some requirements were missing
Lint'ed

Lint is working again (no idea what fixed it), so the warnings have been
fixed up now.
Timeout and Force options
Get specs working
Merge pull request #1 from fromonesrc/master

Get specs working
Merge pull request #10 from paulcollinsiii/master

Minor support for virtualenvwrapper