[1.1.X] Fixed #11859. Allowed subclasses of tuple or list for choice options....

[1.1.X] Fixed #11859. Allowed subclasses of tuple or list for choice options. Backport of r12535 from trunk.


git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.1.X@12536 bcc190cf-cafb-0310-a4f2-bffc1f526a37