Fixed #14459 -- converted many_to_one_regress tests from doctests to...

Fixed #14459 -- converted many_to_one_regress tests from doctests to unittests.  We have always been at war with doctests.  Patch from Gabriel Hurley.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14210 bcc190cf-cafb-0310-a4f2-bffc1f526a37