Use oslo-config-2013.1b4

The cfg API is now available via the oslo-config library, so switch to
it and remove the copied-and-pasted version.

Add the 2013.1b4 tarball to tools/pip-requires - this will be changed
to 'oslo-config>=2013.1' when oslo-config is published to pypi. This
will happen in time for grizzly final.

Add dependency_links to setup.py so that oslo-config can be installed
from the tarball URL specified in pip-requires.

Remove the 'deps = pep8==1.3.3' from tox.ini as it means all the other
deps get installed with easy_install which can't install oslo-config
from the URL.

Make tools/hacking.py include oslo in IMPORT_EXCEPTIONS like it already
does for paste. It turns out imp.find_module() doesn't correct handle
namespace packages.

Retain dummy cfg.py file until keystoneclient middleware has been
updated (I18c450174277c8e2d15ed93879da6cd92074c27a).

Change-Id: I4815aeb8a9341a31a250e920157f15ee15cfc5bc

nova/servicegroup/api.py

@@ -17,14 +17,14 @@
 
 """Define APIs for the servicegroup access."""
 
-from nova.openstack.common import cfg
+import random
+
+from oslo.config import cfg
+
 from nova.openstack.common import importutils
 from nova.openstack.common import log as logging
 from nova import utils
 
-import random
-
-
 LOG = logging.getLogger(__name__)
 _default_driver = 'db'
 servicegroup_driver_opt = cfg.StrOpt('servicegroup_driver',

nova/servicegroup/drivers/db.py

@@ -14,9 +14,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from oslo.config import cfg
+
 from nova import conductor
 from nova import context
-from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
 from nova.openstack.common import timeutils
 from nova.servicegroup import api

nova/servicegroup/drivers/mc.py

@@ -18,10 +18,11 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from oslo.config import cfg
+
 from nova.common import memorycache
 from nova import conductor
 from nova import context
-from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
 from nova.openstack.common import timeutils
 from nova.servicegroup import api

nova/servicegroup/drivers/zk.py

@@ -21,10 +21,10 @@ import os
 import eventlet
 import evzookeeper
 from evzookeeper import membership
+from oslo.config import cfg
 import zookeeper
 
 from nova import exception
-from nova.openstack.common import cfg
 from nova.openstack.common import log as logging
 from nova.servicegroup import api
 from nova import utils