Adding commands for managing layouts.

Adding support for wiping out regions and layouts.
Refactored UI layout manager to allow public knowledge of default layout id.
Enhanced test topo for layout hierarchy.

Change-Id: I254fd494175e753f542f12a664618c1a83f72127
diff --git a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
index 10cd72f..67d9df1 100644
--- a/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
+++ b/core/store/serializers/src/main/java/org/onosproject/store/serializers/KryoNamespaces.java
@@ -195,6 +195,9 @@
 import org.onosproject.net.packet.DefaultPacketRequest;
 import org.onosproject.net.packet.PacketPriority;
 import org.onosproject.net.provider.ProviderId;
+import org.onosproject.net.region.DefaultRegion;
+import org.onosproject.net.region.Region;
+import org.onosproject.net.region.RegionId;
 import org.onosproject.net.resource.ContinuousResource;
 import org.onosproject.net.resource.ContinuousResourceId;
 import org.onosproject.net.resource.DiscreteResource;
@@ -504,6 +507,10 @@
             .register(new AnnotationsSerializer(), DefaultAnnotations.class)
             .register(new ExtensionInstructionSerializer(), Instructions.ExtensionInstructionWrapper.class)
             .register(new ExtensionCriterionSerializer(), ExtensionCriterion.class)
+            .register(Region.class)
+            .register(Region.Type.class)
+            .register(RegionId.class)
+            .register(DefaultRegion.class)
             .register(ExtensionSelectorType.class)
             .register(ExtensionTreatmentType.class)
             .register(TransactionId.class)