all: InterestHeader and ContentObjectHeader refactoring to Interest and ContentObject

refs #29
diff --git a/utils/tracers/ndn-l3-aggregate-tracer.h b/utils/tracers/ndn-l3-aggregate-tracer.h
index a04df67..c3f437b 100644
--- a/utils/tracers/ndn-l3-aggregate-tracer.h
+++ b/utils/tracers/ndn-l3-aggregate-tracer.h
@@ -83,39 +83,39 @@
 
   virtual void
   OutInterests  (std::string context,
-                 Ptr<const InterestHeader>, Ptr<const Face>);
+                 Ptr<const Interest>, Ptr<const Face>);
 
   virtual void
   InInterests   (std::string context,
-                 Ptr<const InterestHeader>, Ptr<const Face>);
+                 Ptr<const Interest>, Ptr<const Face>);
 
   virtual void
   DropInterests (std::string context,
-                 Ptr<const InterestHeader>, Ptr<const Face>);
+                 Ptr<const Interest>, Ptr<const Face>);
   
   virtual void
   OutNacks  (std::string context,
-             Ptr<const InterestHeader>, Ptr<const Face>);
+             Ptr<const Interest>, Ptr<const Face>);
 
   virtual void
   InNacks   (std::string context,
-             Ptr<const InterestHeader>, Ptr<const Face>);
+             Ptr<const Interest>, Ptr<const Face>);
 
   virtual void
   DropNacks (std::string context,
-             Ptr<const InterestHeader>, Ptr<const Face>);
+             Ptr<const Interest>, Ptr<const Face>);
   
   virtual void
   OutData  (std::string context,
-            Ptr<const ContentObjectHeader>, Ptr<const Packet>, bool fromCache, Ptr<const Face>);
+            Ptr<const ContentObject>, Ptr<const Packet>, bool fromCache, Ptr<const Face>);
 
   virtual void
   InData   (std::string context,
-            Ptr<const ContentObjectHeader>, Ptr<const Packet>, Ptr<const Face>);
+            Ptr<const ContentObject>, Ptr<const Packet>, Ptr<const Face>);
 
   virtual void
   DropData (std::string context,
-            Ptr<const ContentObjectHeader>, Ptr<const Packet>, Ptr<const Face>);
+            Ptr<const ContentObject>, Ptr<const Packet>, Ptr<const Face>);
 
 protected:
   void