Fixed #11447 -- Ensured that ForeignKey widgets in a list-editable admin...

Fixed #11447 -- Ensured that ForeignKey widgets in a list-editable admin changelist won't wrap split the widget. Thanks to patrick@vonautomatisch.at for the report, and Julien Phalip for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15656 bcc190cf-cafb-0310-a4f2-bffc1f526a37