Fixed #13455 -- Clarified the interaction of values() and extra(). Thanks to...

Fixed #13455 -- Clarified the interaction of values() and extra(). Thanks to Rupe for the report and draft text.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13145 bcc190cf-cafb-0310-a4f2-bffc1f526a37