Kryo related fixes

- KryoNamespace to allow control over registration id

Change-Id: Idc2a0e27a09916657c725ee97e4366109144cc66
diff --git a/utils/netty/src/main/java/org/onlab/netty/Endpoint.java b/utils/netty/src/main/java/org/onlab/netty/Endpoint.java
index ca24e4f..50bc58d 100644
--- a/utils/netty/src/main/java/org/onlab/netty/Endpoint.java
+++ b/utils/netty/src/main/java/org/onlab/netty/Endpoint.java
@@ -22,20 +22,11 @@
 /**
  * Representation of a TCP/UDP communication end point.
  */
-public class Endpoint {
+public final class Endpoint {
 
     private final int port;
     private final String host;
 
-    /**
-     * Used for serialization.
-     */
-    @SuppressWarnings("unused")
-    private Endpoint() {
-        port = 0;
-        host = null;
-    }
-
     public Endpoint(String host, int port) {
         this.host = host;
         this.port = port;