Change in CcnxApp API.  Now callbacks also contain pointer of original
packet (useful to get packet tags, if they exist)

Reflecting changes in PackegTag API

Rescanning bindings

More work on packet-path-weight tracers
diff --git a/apps/ccnx-app.h b/apps/ccnx-app.h
index ae52048..80a789c 100644
--- a/apps/ccnx-app.h
+++ b/apps/ccnx-app.h
@@ -65,25 +65,27 @@
   /**
    * @brief Method that will be called every time new Interest arrives
    * @param interest Interest header
+   * @param packet   "Payload" of the interests packet. The actual payload should be zero, but packet itself
+   *                 may be useful to get packet tags
    */
   virtual void
-  OnInterest (const Ptr<const CcnxInterestHeader> &interest);
+  OnInterest (const Ptr<const CcnxInterestHeader> &interest, Ptr<Packet> packet);
 
   /**
    * @brief Method that will be called every time new NACK arrives
    * @param interest Interest header
    */
   virtual void
-  OnNack (const Ptr<const CcnxInterestHeader> &interest);
+  OnNack (const Ptr<const CcnxInterestHeader> &interest, Ptr<Packet> packet);
   
   /**
    * @brief Method that will be called every time new ContentObject arrives
    * @param contentObject ContentObject header
-   * @param payload payload (potentially virtual) of the ContentObject packet
+   * @param payload payload (potentially virtual) of the ContentObject packet (may include packet tags of original packet)
    */
   virtual void
   OnContentObject (const Ptr<const CcnxContentObjectHeader> &contentObject,
-                   const Ptr<const Packet> &payload);
+                   Ptr<Packet> payload);
         
 protected:
   virtual void