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/apps/ccnx-producer.cc b/apps/ccnx-producer.cc
index 291fb82..1148767 100644
--- a/apps/ccnx-producer.cc
+++ b/apps/ccnx-producer.cc
@@ -23,7 +23,7 @@
 #include "ns3/log.h"
 #include "ns3/ccnx-interest-header.h"
 #include "ns3/ccnx-content-object-header.h"
-#include "ns3/ccnx-path-stretch-tag.h"
+// #include "ns3/ccnx-path-stretch-tag.h"
 #include "ns3/string.h"
 #include "ns3/uinteger.h"
 #include "ns3/packet.h"
@@ -114,18 +114,18 @@
   NS_LOG_INFO ("Respodning with ContentObject:\n" << boost::cref(*header));
   
   Ptr<Packet> packet = Create<Packet> (m_virtualPayloadSize);
-  Ptr<const WeightsPathStretchTag> tag = origPacket->RemovePacketTag<WeightsPathStretchTag> ();
-  if (tag != 0)
-    {
-      // std::cout << Simulator::Now () << ", " << m_app->GetInstanceTypeId ().GetName () << "\n";
+  // Ptr<const WeightsPathStretchTag> tag = origPacket->RemovePacketTag<WeightsPathStretchTag> ();
+  // if (tag != 0)
+  //   {
+  //     // std::cout << Simulator::Now () << ", " << m_app->GetInstanceTypeId ().GetName () << "\n";
 
-      // echo back WeightsPathStretchTag
-      packet->AddPacketTag (CreateObject<WeightsPathStretchTag> (*tag));
+  //     // echo back WeightsPathStretchTag
+  //     packet->AddPacketTag (CreateObject<WeightsPathStretchTag> (*tag));
 
-      // \todo
-      // packet->AddPacketTag should actually accept Ptr<const WeightsPathStretchTag> instead of
-      // Ptr<WeightsPathStretchTag>.  Echoing will be simplified after change is done
-    }
+  //     // \todo
+  //     // packet->AddPacketTag should actually accept Ptr<const WeightsPathStretchTag> instead of
+  //     // Ptr<WeightsPathStretchTag>.  Echoing will be simplified after change is done
+  //   }
   
   m_transmittedContentObjects (header, packet, this, m_face);