Since it triggers imports, it shouldn't be done lightly. This commit adds a public API for doing it explicitly, django.setup(), and does it automatically when using manage.py and wsgi.py.
Refs #1796, #21676.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@17022 bcc190cf-cafb-0310-a4f2-bffc1f526a37