Revert "Merge pull request #687 from dstufft/dont-import-site"

This reverts commit eb88e8f7b20b5d0809013100dc14fe2ebbf738da, reversing
changes made to 6fc1ffa65c7e00e6065522ba3b88ee47e8236dd3.

(cherry picked from commit d73e30180ac8e6f6ad365d43fd3693afdcd51eaa)
Merge pull request #690 from dstufft/undo-things

I hate computers.
(cherry picked from commit 6d3073e973d3db8ec616b8c7d40745dd43a50f82)
bump verison for 12.0.4
Merge branch 'release/12.0.4'
Merge branch 'master' into develop

Conflicts:
	docs/changes.rst
	virtualenv.py