Use cfg's new global CONF object

Implements blueprint cfg-global-object

Replace nova.flags.FLAGS with openstack.common.cfg.CONF.

In future, we can do a s/FLAGS/CONF/ across the codebase.

Change-Id: Ib293873089a5399febd7a3b0410f66e9bef115f1

nova/test.py

@@ -128,6 +128,7 @@ class TestCase(unittest.TestCase):
         super(TestCase, self).setUp()
 
         fake_flags.set_defaults(FLAGS)
+        flags.parse_args([], default_config_files=[])
 
         # NOTE(vish): We need a better method for creating fixtures for tests
         #             now that we have some required db setup for the system