Fixed #14232 -- Clarified the data type of date_list in date-based generic...

Fixed #14232 -- Clarified the data type of date_list in date-based generic views. Thanks to clelland for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14020 bcc190cf-cafb-0310-a4f2-bffc1f526a37