Fixed #7672 -- Added a 'week_day' lookup type. Many thanks to Ross Poulton for...

Fixed #7672 -- Added a 'week_day' lookup type. Many thanks to Ross Poulton for the proposal and implementation on all built-in database backends..


git-svn-id: http://code.djangoproject.com/svn/django/trunk@9818 bcc190cf-cafb-0310-a4f2-bffc1f526a37