all: InterestHeader and ContentObjectHeader refactoring to Interest and ContentObject

refs #29
diff --git a/model/fw/green-yellow-red.h b/model/fw/green-yellow-red.h
index e82c93b..1c4dcde 100644
--- a/model/fw/green-yellow-red.h
+++ b/model/fw/green-yellow-red.h
@@ -44,7 +44,7 @@
 
   virtual bool
   DoPropagateInterest (Ptr<Face> inFace,
-                       Ptr<const InterestHeader> header,
+                       Ptr<const Interest> header,
                        Ptr<const Packet> origPacket,
                        Ptr<pit::Entry> pitEntry);
 
@@ -54,7 +54,7 @@
   virtual void
   DidReceiveValidNack (Ptr<Face> incomingFace,
                        uint32_t nackCode,
-                       Ptr<const InterestHeader> header,
+                       Ptr<const Interest> header,
                        Ptr<const Packet> origPacket,
                        Ptr<pit::Entry> pitEntry);
 private: