[1.0.X] Fixed #9932 -- Added a validation error when an inline tries to...

[1.0.X] Fixed #9932 -- Added a validation error when an inline tries to exclude the foreign key that provides the link to the parent model. Thanks to david for the report and patch.

Merge of r10668 from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.0.X@10672 bcc190cf-cafb-0310-a4f2-bffc1f526a37