FlowRule private extension refactor.
1.merge private flow into regular flowrule subsystem.no mirror code any
more.no change flowrule api.
2.define a rich-data-type to carry private flow.
3.modify OpenFlowRuleProvider.class to support for 3rd party private
flow.i don't know whether is suitable.because this class name is
relative with open flow protocal.
4.fix some junit test bug caused by modification of FlowRule interface.

Change-Id: I6c54d1e97f231a75bd1b416f0893e0379613d7ce
diff --git a/web/api/src/test/java/org/onosproject/rest/FlowsResourceTest.java b/web/api/src/test/java/org/onosproject/rest/FlowsResourceTest.java
index a460385..0f0dae8 100644
--- a/web/api/src/test/java/org/onosproject/rest/FlowsResourceTest.java
+++ b/web/api/src/test/java/org/onosproject/rest/FlowsResourceTest.java
@@ -40,12 +40,14 @@
 import org.onosproject.net.flow.DefaultTrafficTreatment;
 import org.onosproject.net.flow.FlowEntry;
 import org.onosproject.net.flow.FlowId;
+import org.onosproject.net.flow.FlowRuleExtPayLoad;
 import org.onosproject.net.flow.FlowRuleService;
 import org.onosproject.net.flow.TrafficSelector;
 import org.onosproject.net.flow.TrafficTreatment;
 import org.onosproject.net.flow.criteria.Criterion;
 import org.onosproject.net.flow.instructions.Instruction;
 import org.onosproject.net.flow.instructions.Instructions;
+
 import com.eclipsesource.json.JsonArray;
 import com.eclipsesource.json.JsonObject;
 import com.google.common.collect.ImmutableSet;
@@ -190,6 +192,11 @@
         public int tableId() {
             return 0;
         }
+
+        @Override
+        public FlowRuleExtPayLoad payLoad() {
+            return null;
+        }
     }
 
     /**