Reimplemented the ProxyArp app on top of the NeighbourResolutionService.

Also some small API changes to track app ID of handler registrations, and
improved interface matching in NeighbourPacketManager.

Added CLI to view handler registrations.

Change-Id: I8cd0b91a16d9ec60287b65f9d8fc5e3cd87560e8
diff --git a/incubator/net/src/main/java/org/onosproject/incubator/net/neighbour/impl/DefaultNeighbourMessageContext.java b/incubator/net/src/main/java/org/onosproject/incubator/net/neighbour/impl/DefaultNeighbourMessageContext.java
index e056f79..44e97f9 100644
--- a/incubator/net/src/main/java/org/onosproject/incubator/net/neighbour/impl/DefaultNeighbourMessageContext.java
+++ b/incubator/net/src/main/java/org/onosproject/incubator/net/neighbour/impl/DefaultNeighbourMessageContext.java
@@ -105,7 +105,12 @@
 
     @Override
     public MacAddress srcMac() {
-        return MacAddress.valueOf(eth.getSourceMACAddress());
+        return eth.getSourceMAC();
+    }
+
+    @Override
+    public MacAddress dstMac() {
+        return eth.getDestinationMAC();
     }
 
     @Override