Fixed #5034 -- honor request.urlconf in reverse and resolve.

This enables {% url %} to honor request.urlconf set from process_request
middleware methods.

Thanks SmileyChris for the initial patch work.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11740 bcc190cf-cafb-0310-a4f2-bffc1f526a37