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

Refs #1005 (http://redmine.named-data.net/)
diff --git a/model/cs/content-store-impl.h b/model/cs/content-store-impl.h
index 9cd934e..69fa00e 100644
--- a/model/cs/content-store-impl.h
+++ b/model/cs/content-store-impl.h
@@ -156,7 +156,7 @@
 }
 
 template<class Policy>
-Ptr<const ContentObject>
+Ptr<ContentObject>
 ContentStoreImpl<Policy>::Lookup (Ptr<const Interest> interest)
 {
   NS_LOG_FUNCTION (this << interest->GetName ());
@@ -168,7 +168,7 @@
     {
       this->m_cacheHitsTrace (interest, node->payload ()->GetData ());
 
-      Ptr<ContentObject> copy = Create<ContentObject> (node->payload ()->GetData ());
+      Ptr<ContentObject> copy = Create<ContentObject> (*node->payload ()->GetData ());
       ConstCast<Packet> (copy->GetPayload ())->RemoveAllPacketTags ();
       return copy;
     }