model: Returning back support for CCNb wire format

Refs #1008 (http://redmine.named-data.net/)
diff --git a/model/ndn-content-object.cc b/model/ndn-content-object.cc
index 81d92f0..ecf3197 100644
--- a/model/ndn-content-object.cc
+++ b/model/ndn-content-object.cc
@@ -120,6 +120,18 @@
 }
 
 void
+ContentObject::SetKeyLocator (Ptr<Name> keyLocator)
+{
+  m_keyLocator = keyLocator;
+}
+
+Ptr<const Name>
+ContentObject::GetKeyLocator () const
+{
+  return m_keyLocator;
+}
+
+void
 ContentObject::Print (std::ostream &os) const
 {
   os << "D: " << GetName ();