[1.2.X] Fixed #13880 - added 2.7 to list of supported versions of Python

Thanks Alex

Backport of [13423] from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@13424 bcc190cf-cafb-0310-a4f2-bffc1f526a37