[1.0.X] Fixed #10163: add an artificial ordering to querysets used by...

[1.0.X] Fixed #10163: add an artificial ordering to querysets used by formsets, thus ensuring that POSTed data "lines up" correctly every time. Thanks to Karen Tracey for pointing in the right direction here.

This is a backport of [10625] from trunk, in a sense. In 1.1 I added a `QuerySet.ordered` property to deal with the logic of determining whether a queryset has ordering, but we can't add new features on a bugfix branch. So here in 1.0-land, the logic has to live in the formset. This smells, but it's better than having a bug.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10630 bcc190cf-cafb-0310-a4f2-bffc1f526a37