Adding device type

Adding device type on port(eg Ethernet Port,TPort,WPort), Link(Ethernet,Optical..) and Switch(Ethernet,Optical)
Updated Serializers.
Fixed javadoc issue for Enums.

ONOS-1428

Change-Id: Id3e3094f1fbf90154fff9a61e3c0ca36be69c281
diff --git a/src/main/java/net/onrc/onos/core/topology/Port.java b/src/main/java/net/onrc/onos/core/topology/Port.java
index 2e428c7..5419c02 100644
--- a/src/main/java/net/onrc/onos/core/topology/Port.java
+++ b/src/main/java/net/onrc/onos/core/topology/Port.java
@@ -133,4 +133,12 @@
      * @return {@link Host}s attached to this port
      */
     public Collection<Host> getHosts();
+
+
+    /**
+     * Returns the port type of this port.
+     *
+     * @return {@link PortType}
+     */
+    public PortType getPortType();
 }