This also removes the need for ADMIN_MEDIA_PREFIX and replaces it with the convention to find admin's static files at STATIC_URL + 'admin/'.
Thanks to Jacob for the review and general help.
git-svn-id: http://code.djangoproject.com/svn/django/trunk@16487 bcc190cf-cafb-0310-a4f2-bffc1f526a37