Log Message:
Update to 12.0.4:

12.0.4 (2014-22-23)
~~~~~~~~~~~~~~~~~~~

* Revert the fix to ``-p`` on Debian based pythons as it was broken in other
  situations.

* Revert several sys.path changes new in 12.0 which were breaking virtualenv.

12.0.3 (2014-22-23)
~~~~~~~~~~~~~~~~~~~

* Fix an issue where Debian based Pythons would fail when using -p with the
  host Python.

* Upgrade pip to 6.0.3

12.0.2 (2014-12-23)
~~~~~~~~~~~~~~~~~~~

* Upgraded pip to 6.0.2

12.0.1 (2014-12-22)
~~~~~~~~~~~~~~~~~~~

* Upgraded pip to 6.0.1

12.0 (2014-12-22)
~~~~~~~~~~~~~~~~~

* **PROCESS** Version numbers are now simply ``X.Y`` where the leading ``1``
  has been dropped.
* Split up documentation into structured pages
* Now using pytest framework
* Correct sys.path ordering for debian, issue #461
* Correctly throws error on older Pythons, issue #619
* Allow for empty $PATH, pull #601
* Don't set prompt if $env:VIRTUAL_ENV_DISABLE_PROMPT is set for Powershell
* Updated setuptools to 7.0