Make it possible to reconnect BBitmap to the app_server.

* maintain a list of all BBitmaps
* refactor the client memory allocator class, its possible now to just clone existing client area

headers/os/interface/Bitmap.h

@@ -110,10 +110,12 @@ public:
 
 			BBitmap&			operator=(const BBitmap& source);
 
+	class Private;
 private:
 	friend class BView;
 	friend class BApplication;
 	friend class BPrivate::BPrivateScreen;
+	friend class Private;
 
 	virtual	status_t			Perform(perform_code d, void* arg);
 	virtual	void				_ReservedBitmap1();
@@ -127,6 +129,8 @@ private:
 			void				_CleanUp();
 			void				_AssertPointer();
 
+			void				_ReconnectToAppServer();
+
 private:
 			uint8*				fBasePointer;
 			int32				fSize;