Added tools for converting dpid to uri and vice versa.
Modified device and link provider to use the new tools.
diff --git a/core/trivial/src/main/java/org/onlab/onos/net/trivial/topology/impl/SimpleTopologyManager.java b/core/trivial/src/main/java/org/onlab/onos/net/trivial/topology/impl/SimpleTopologyManager.java
index 6ad8f4b..6831578 100644
--- a/core/trivial/src/main/java/org/onlab/onos/net/trivial/topology/impl/SimpleTopologyManager.java
+++ b/core/trivial/src/main/java/org/onlab/onos/net/trivial/topology/impl/SimpleTopologyManager.java
@@ -189,8 +189,7 @@
             TopologyEvent event = store.updateTopology(provider().id(),
                                                        topoDescription, reasons);
             if (event != null) {
-                log.info("Topology {} changed due to: {}", event.subject(),
-                         reasons == null ? "initial compute" : reasons);
+                log.info("Topology {} changed", event.subject());
                 eventDispatcher.post(event);
             }
         }