Topology interface to use Dpid, PortNumber

- Modified Switch interface to use Dpid, PortNumber instead of Long
- Modified Port interface to use Dpid, PortNumber instead of Long
- Modified Topology interface which uses Dpid, PortNumber, SwitchPort

- PortImpl#toString() format has changed: "%d:%d" -> "Dpid#toString():PortNumber#toString"

- Part of ONOS-1564

Change-Id: I8decdbb2fb0cce9e087ad49af3a087b65b8511d7
diff --git a/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java b/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
index 554651e..4e9418a 100644
--- a/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
+++ b/src/main/java/net/onrc/onos/core/topology/SwitchEvent.java
@@ -25,8 +25,8 @@
         this.dpid = new Dpid(dpid);
     }
 
-    public Long getDpid() {
-        return dpid.value();
+    public Dpid getDpid() {
+        return dpid;
     }
 
     @Override