[1.2.X] Converted United States localflavor doctests into unittests. We have...

[1.2.X] Converted United States localflavor doctests into unittests.  We have always been at war with doctests.  Thanks to Idan Gazit.  Backport of [14954].

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14978 bcc190cf-cafb-0310-a4f2-bffc1f526a37