Added a LogicalClockService for ordering arbitrary events in the cluster. Updated couple of areas that are currently vulnerable to clock skew

Change-Id: I14548ecb3c783104de8d72cbb5eb21de6ece08ed
diff --git a/core/store/dist/src/test/java/org/onosproject/store/ecmap/EventuallyConsistentMapImplTest.java b/core/store/dist/src/test/java/org/onosproject/store/ecmap/EventuallyConsistentMapImplTest.java
index 8629fcd..0a3d5e6 100644
--- a/core/store/dist/src/test/java/org/onosproject/store/ecmap/EventuallyConsistentMapImplTest.java
+++ b/core/store/dist/src/test/java/org/onosproject/store/ecmap/EventuallyConsistentMapImplTest.java
@@ -20,6 +20,7 @@
 import com.google.common.collect.Lists;
 import com.google.common.util.concurrent.ListenableFuture;
 import com.google.common.util.concurrent.MoreExecutors;
+
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
@@ -35,6 +36,7 @@
 import org.onosproject.store.cluster.messaging.ClusterMessageHandler;
 import org.onosproject.store.cluster.messaging.MessageSubject;
 import org.onosproject.store.service.ClockService;
+import org.onosproject.store.impl.LogicalTimestamp;
 import org.onosproject.store.impl.WallClockTimestamp;
 import org.onosproject.store.serializers.KryoNamespaces;
 import org.onosproject.store.serializers.KryoSerializer;
@@ -102,6 +104,7 @@
                     .register(KryoNamespaces.API)
                     .register(TestTimestamp.class)
                     // Below is the classes that the map internally registers
+                    .register(LogicalTimestamp.class)
                     .register(WallClockTimestamp.class)
                     .register(PutEntry.class)
                     .register(RemoveEntry.class)