[1.0.X] Fixed #9493 -- Corrected error handling of formsets that violate...

[1.0.X] Fixed #9493 -- Corrected error handling of formsets that violate unique constraints across the component forms. Thanks to Alex Gaynor for the patch.

Merge of r10682 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10718 bcc190cf-cafb-0310-a4f2-bffc1f526a37