Rename Port to PortNumber

Current util.Port actually only represent a port number.
Renaming it to PortNumber, so that it matches what it actually reprsent.

- Updated javadoc
- Removed unnecessary hashCode calculation
- Hide default constructor from public

Change-Id: Ib26c746eaa27464356c4ca0abff6af5e321afc35
diff --git a/src/main/java/net/onrc/onos/apps/sdnip/Interface.java b/src/main/java/net/onrc/onos/apps/sdnip/Interface.java
index b906ba6..de3b48c 100644
--- a/src/main/java/net/onrc/onos/apps/sdnip/Interface.java
+++ b/src/main/java/net/onrc/onos/apps/sdnip/Interface.java
@@ -3,7 +3,7 @@
 import java.net.InetAddress;
 
 import net.onrc.onos.core.util.Dpid;
-import net.onrc.onos.core.util.Port;
+import net.onrc.onos.core.util.PortNumber;
 import net.onrc.onos.core.util.SwitchPort;
 
 import org.codehaus.jackson.annotate.JsonCreator;
@@ -73,7 +73,7 @@
     public SwitchPort getSwitchPort() {
         //TODO SwitchPort, Dpid and Port are mutable, but they could probably
         //be made immutable which would prevent the need to copy
-        return new SwitchPort(new Dpid(dpid), new Port(port));
+        return new SwitchPort(new Dpid(dpid), new PortNumber(port));
     }
 
     /**