model: First set of major API changes and reorganizations

Main motive: change interface in Face class, resulting in need to change forwarding strategy interfaces

Refs #1005 (http://redmine.named-data.net/)
diff --git a/model/ndn-net-device-face.h b/model/ndn-net-device-face.h
index 651a7ae..d001015 100644
--- a/model/ndn-net-device-face.h
+++ b/model/ndn-net-device-face.h
@@ -60,12 +60,14 @@
   ////////////////////////////////////////////////////////////////////
   // methods overloaded from NdnFace
   virtual void
-  RegisterProtocolHandler (ProtocolHandler handler);
+  RegisterProtocolHandlers (const InterestHandler &interestHandler, const DataHandler &dataHandler);
+
+  virtual void
+  UnRegisterProtocolHandlers ();
   
 protected:
-  // also from NdnFace
   virtual bool
-  SendImpl (Ptr<Packet> p);
+  Send (Ptr<Packet> p);
 
 public:
   /**