Added distributed transaction support through a two phase commit protocol

Change-Id: I85d64234a24823fee8b3c2ea830abbb6867dad38
diff --git a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseSerializer.java b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseSerializer.java
index 237c85b..f6fa6d1 100644
--- a/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseSerializer.java
+++ b/core/store/dist/src/main/java/org/onosproject/store/consistent/impl/DatabaseSerializer.java
@@ -23,6 +23,8 @@
 import org.onlab.util.KryoNamespace;
 import org.onosproject.store.serializers.KryoNamespaces;
 import org.onosproject.store.serializers.KryoSerializer;
+import org.onosproject.store.service.DatabaseUpdate;
+import org.onosproject.store.service.Transaction;
 import org.onosproject.store.service.Versioned;
 
 import net.kuujo.copycat.cluster.internal.MemberInfo;
@@ -63,8 +65,14 @@
     private static final KryoNamespace ONOS_STORE = KryoNamespace.newBuilder()
             .nextId(KryoNamespace.FLOATING_ID)
             .register(Versioned.class)
+            .register(DatabaseUpdate.class)
+            .register(DatabaseUpdate.Type.class)
             .register(Pair.class)
             .register(ImmutablePair.class)
+            .register(Result.class)
+            .register(Result.Status.class)
+            .register(DefaultTransaction.class)
+            .register(Transaction.State.class)
             .build();
 
     private static final KryoSerializer SERIALIZER = new KryoSerializer() {