[ONOS-4015] Implement Region administration CLI

- Implement region add/update/remove CLI
- Implement devices add/remove CLI

Change-Id: I38b40b24df7f864b0725104f63347081257743ac
diff --git a/cli/src/main/java/org/onosproject/cli/Comparators.java b/cli/src/main/java/org/onosproject/cli/Comparators.java
index 530c296..8df9d51 100644
--- a/cli/src/main/java/org/onosproject/cli/Comparators.java
+++ b/cli/src/main/java/org/onosproject/cli/Comparators.java
@@ -26,6 +26,7 @@
 import org.onosproject.net.Port;
 import org.onosproject.net.flow.FlowRule;
 import org.onosproject.net.group.Group;
+import org.onosproject.net.region.Region;
 import org.onosproject.net.statistic.TypedFlowEntryWithLoad;
 import org.onosproject.net.topology.TopologyCluster;
 
@@ -141,4 +142,11 @@
             return deviceKey1.deviceKeyId().id().toString().compareTo(deviceKey2.deviceKeyId().id().toString());
         }
     };
+
+    public static final Comparator<Region> REGION_COMPARATOR = new Comparator<Region>() {
+        @Override
+        public int compare(Region region1, Region region2) {
+            return region1.id().toString().compareTo(region2.id().toString());
+        }
+    };
 }