Revert "Append Django app's base folder to sys.path from manage.py."

This reverts commit c06f42d35b03c22a70f6956973f1da1316a61931.
Revert "Fix broken imports in fabfiles."

This reverts commit 2057c3e69e5b77671accbd4aebc83d4162dc2e98.
Minor changges after comments from Greg.