[1.2.X] Removed all usages of deprecated TestCase methods (self.fail*). This...

[1.2.X] Removed all usages of deprecated TestCase methods (self.fail*).  This removed most of the Warnings emitted (with -Wall) during the test suite. Backport of [14803].

git-svn-id: http://code.djangoproject.com/svn/django/branches/releases/1.2.X@14805 bcc190cf-cafb-0310-a4f2-bffc1f526a37