Original Launchpad bug 366946: https://bugs.launchpad.net/ipython/+bug/366946
Reported by: ellisonbg (Brian Granger).
For twisted using tests, we used to use testing.util.DeferredTestCase. All usage of this should be removed and replace with twisted.trial.unittest.TestCase. Also, testing.util should be removed.
This will simply go away with the new parallel stuff.
ability to create playlists. closes #83