When giving up PIT entry, remove all outgoing interests. Otherwise,
everything can stuck (was happening...)

Modified experiment with synthetic topology
diff --git a/model/ccnx-pit-entry.cc b/model/ccnx-pit-entry.cc
index 76c7997..0cc6509 100644
--- a/model/ccnx-pit-entry.cc
+++ b/model/ccnx-pit-entry.cc
@@ -140,6 +140,7 @@
 void
 CcnxPitEntry::IncreaseAllowedRetxCount ()
 {
+  NS_LOG_ERROR (this);
   m_maxRetxCount++;
 }