Finalizing interest limits. Now everything seem to work.

To work correctly, a lot of parameters have to be adjusted, including average
contentObject size, averageRTT, queues on nodes.
diff --git a/apps/ccnx-consumer.cc b/apps/ccnx-consumer.cc
index 5d2ce7c..dc54f92 100644
--- a/apps/ccnx-consumer.cc
+++ b/apps/ccnx-consumer.cc
@@ -136,7 +136,10 @@
   interestHeader.SetName                (nameWithSequence);
   interestHeader.SetInterestLifetime    (m_interestLifeTime);
   interestHeader.SetChildSelector       (m_childSelector);
-  interestHeader.SetExclude             (Create<CcnxNameComponents> (m_exclude));
+  if (m_exclude.size ()>0)
+    {
+      interestHeader.SetExclude             (Create<CcnxNameComponents> (m_exclude));
+    }
   interestHeader.SetMaxSuffixComponents (m_maxSuffixComponents);
   interestHeader.SetMinSuffixComponents (m_minSuffixComponents);