Finalizing PathWeight tracing

Now tracing is moved to CcnxConsumer
diff --git a/model/ccnx-path-stretch-tag.h b/model/ccnx-path-stretch-tag.h
index 71a4582..644871f 100644
--- a/model/ccnx-path-stretch-tag.h
+++ b/model/ccnx-path-stretch-tag.h
@@ -52,12 +52,15 @@
   void
   AddPathInfo (Ptr<Node> node, uint32_t weight);
 
-  uint32_t
+  uint64_t
   GetTotalWeight () const;
 
   Ptr<Node>
   GetSourceNode () const;
 
+  Ptr<Node>
+  GetDestinationNode () const;
+
   const std::list<NodeWeightPair> &
   GetInfos () const
   { return m_infos; }