Fixed #6932 -- Added a template tag that gives a list of available flatpages for a given user. Thanks to Dmitri Fedortchenko for the suggestion, and to Mnewman, faldridge and Simon Meers for their work on the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@13654 bcc190cf-cafb-0310-a4f2-bffc1f526a37