Merge "Fix SG interface to reflect the reality"

diff --cc quantum/db/securitygroups_db.py
Simple merge

diff --cc quantum/extensions/securitygroup.py
index 6c43ac48b8a3c7eb2e9c3ea37882484da1528bd8,8dd342e4cdaf6f01e9df6cb82f3dc3ad205a87c2..f81b99c8fccc426653c468cfdfbd3f182a9f6ae5
--- 1/quantum/extensions/securitygroup.py
--- 2/quantum/extensions/securitygroup.py
+++ b/quantum/extensions/securitygroup.py
@@@ -15,10 -15,9 +15,11 @@@
  #    License for the specific language governing permissions and limitations
  #    under the License.
  
+ from abc import ABCMeta
  from abc import abstractmethod
  
 +from oslo.config import cfg
 +
  from quantum.api import extensions
  from quantum.api.v2 import attributes as attr
  from quantum.api.v2 import base