WARNING: make a backup copy of your local config.py before pulling
this change, as Git will overwrite it without warning.
The configuration defaults to deployment settings, allowing overrides.
Overrides are read from config_local.py and from the file pointed to
by the PILLAR_CONFIG env var.
Also converted test_auth.py to use the new AbstractPillarTest class.
This class ensures that we test against the testing database, which
is dropped at every setUp()/tearDown().