Fixed #12143 -- Corrected the naming of the 'to' column in recursive m2m models. Thanks to knutin@gmail.com for the report, and Alex Gaynor for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@11713 bcc190cf-cafb-0310-a4f2-bffc1f526a37