Backport PR
#4018: Fix warning when running IPython.kernel tests...
Backport PR
#4018: Fix warning when running IPython.kernel tests
The signature of TemporaryDirectory.cleanup() changed just before Python 3.2, and our TemporaryWorkingDirectory subclass was receiving an unexpected parameter. This copies in a newer TemporaryDirectory.cleanup() implementation for Python 2.7, and tweaks the subclass to accept the extra parameter.