Allow BMediaRoster to log local nodes

* BMediaRoster is now capable to know which nodes are
instantiated in this team. This is also a first step to make
them survive after media_server crashes.
* A control at BMediaRoster::Quit can notify if all nodes
were correctly released. Ideally at this point the local nodes
list should be empty.

headers/private/media/MediaRosterEx.h

@@ -92,6 +92,9 @@ public:
 
 		status_t			BuildConnections();
 
+		void				RegisterLocalNode(BMediaNode* node);
+		void				UnregisterLocalNode(BMediaNode* node);
+
 private:
 	friend class BMediaRoster;
 };