proxy: Workaround for threading lib bug

In order to avoid a (harmless) exception from the threading library
(fixed in Python 3.3), we should make sure to call patch_thread() before
threading gets imported and import threading from the main Python
thread [1][2].

[1] http://bugs.python.org/issue1596321
[2] http://stackoverflow.com/questions/8774958/keyerror-in-module-threading-after-a-successful-py-test-run
Add console_script entry point for client