model: Another set of refactoring/renaming to make code compile (not tested yet)

Refs #1005 (http://redmine.named-data.net/)
diff --git a/model/pit/ndn-pit.cc b/model/pit/ndn-pit.cc
index ea84496..079cf3f 100644
--- a/model/pit/ndn-pit.cc
+++ b/model/pit/ndn-pit.cc
@@ -27,6 +27,7 @@
 #include "ns3/nstime.h"
 #include "ns3/uinteger.h"
 #include "ns3/simulator.h"
+#include "ns3/packet.h"
 
 #include <boost/lambda/bind.hpp>
 #include <boost/lambda/lambda.hpp>