all: InterestHeader and ContentObjectHeader refactoring to Interest and ContentObject

refs #29
diff --git a/model/cs/ndn-content-store.cc b/model/cs/ndn-content-store.cc
index 98e118d..c99d7ed 100644
--- a/model/cs/ndn-content-store.cc
+++ b/model/cs/ndn-content-store.cc
@@ -60,7 +60,7 @@
 
 //////////////////////////////////////////////////////////////////////
 
-Entry::Entry (Ptr<ContentStore> cs, Ptr<const ContentObjectHeader> header, Ptr<const Packet> packet)
+Entry::Entry (Ptr<ContentStore> cs, Ptr<const ContentObject> header, Ptr<const Packet> packet)
   : m_cs (cs)
   , m_header (header)
   , m_packet (packet->Copy ())
@@ -84,7 +84,7 @@
   return m_header->GetName ();
 }
 
-Ptr<const ContentObjectHeader>
+Ptr<const ContentObject>
 Entry::GetHeader () const
 {
   return m_header;