[issue7712] Add a context manager to change cwd in test.test_support and run the test suite in a temp dir.

[Florent Xicluna]

Changes by Florent Xicluna <laxyf at yahoo.fr>:


----------
title: Add a context manager to change cwd in test.test_support -> Add a context manager to change cwd in test.test_support and run the test suite in a temp dir.

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue7712>
_______________________________________