Allows wsgi server kwargs to be given.

This fix allows someone using openstack.common.wsgi to pass
kwargs down to eventlet.wsgi.server when calling wsgi.run_server.

Fixes bug 1156930

Change-Id: Id35232f68ee40c5435e157a834fc94d4bbd04970
Adds pylint section in tox.ini to check for unused imports

Fixes bug #1157597

Change-Id: I77e0ddb1babf1eec0bb953b8bfa52cd1d415f709
Remove detailed-errors from setup.cfg.

detailed-errors does not provide us any value in our use of runs,
and it actually breaks now that we're using standard unittest
protocol and testtools.

Change-Id: Ie5a36eaf022e3f3d47904aad0ba2efdfc0d85b34
Merge "Adds pylint section in tox.ini to check for unused imports"
Merge "Allows wsgi server kwargs to be given."