Converted the Argentina localflavor doctests to unittests. We have always...

Converted the Argentina localflavor doctests to unittests.  We have always been at war with doctests.  Thanks to Idan Gazit for the patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14872 bcc190cf-cafb-0310-a4f2-bffc1f526a37