[1.2.X] Fixed #14529 -- Fixed representation of model names in admin messages...

[1.2.X] Fixed #14529 -- Fixed representation of model names in admin messages after model object changes when the ModelAdmin queryset() uses defer() or only(). Thanks rlaager for report and initial patch, to rasca an julien for help in tracking the problem.

Backport of [15596] from trunk.

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@15597 bcc190cf-cafb-0310-a4f2-bffc1f526a37