Moving around path weight tagging. Now CcnxFace owns metric field, which is used for tagging.

Correcting bugs in blackhole-sprint scenario.  This time it should be
the right one:
- instead of a hijacker app, all faces on hijacked node are turned down
- there was a trick with RTT estimation (when batch, it is necessary to
  reset history upon a new batch)
- instead of random runs, trying all possible combinations of
  producer/hijacker
diff --git a/helper/tracers/ccnx-path-weight-tracer.cc b/helper/tracers/ccnx-path-weight-tracer.cc
index 4d6aa7d..b2685bd 100644
--- a/helper/tracers/ccnx-path-weight-tracer.cc
+++ b/helper/tracers/ccnx-path-weight-tracer.cc
@@ -36,10 +36,9 @@
 
 namespace ns3 {
     
-CcnxPathWeightTracer::CcnxPathWeightTracer (std::ostream &os, Ptr<Node> node, std::string appId)
+CcnxPathWeightTracer::CcnxPathWeightTracer (std::ostream &os, Ptr<Node> node)
   : m_os (os)
   , m_nodePtr (node)
-  , m_appId (appId)
 {
   m_node = boost::lexical_cast<string> (m_nodePtr->GetId ());
 
@@ -55,16 +54,13 @@
 void
 CcnxPathWeightTracer::Connect ()
 {
-  Config::Set ("/NodeList/"+m_node+"/$ns3::CcnxL3Protocol/ForwardingStrategy/MetricTagging",
+  Config::Set ("/NodeList/"+m_node+"/$ns3::CcnxL3Protocol/FaceList/*/MetricTagging",
                BooleanValue (true));
 
-  Config::Connect ("/NodeList/"+m_node+"/ApplicationList/"+m_appId+"/PathWeightsTrace",
+  Config::Connect ("/NodeList/"+m_node+"/ApplicationList/*/PathWeightsTrace",
                    MakeCallback (&CcnxPathWeightTracer::InLocalFace, this));
-  // Config::Connect ("/NodeList/"+m_node+"/$ns3::CcnxL3Protocol/FaceList/*/$ns3::CcnxLocalFace/PathWeightsTrace",
-  //                  MakeCallback (&CcnxPathWeightTracer::InLocalFace, this));
 }
 
-
 void
 CcnxPathWeightTracer::PrintHeader (std::ostream &os)
 {