Feature to drag a file from Windows to Mac:

- On Mac client main thread is used for cocoa application in order to simulate drag.
- Send dragging file dir from Windows server to Mac client while dragging after switching screen.
- Dragging information sending is immature now (need to support multi files dragging in the future).
- Used Cocoa function to monitor dragg pasteboard.
- Changed Mac client to use another thread for event queue instead of the main thread.
- Change fileRecieveComplete to fileRecieveCompleted.

src/lib/platform/CXWindowsEventQueueBuffer.h

@@ -45,6 +45,8 @@ public:
 						newTimer(double duration, bool oneShot) const;
 	virtual void		deleteTimer(CEventQueueTimer*) const;
 
+	virtual	void		cacheCurrentEventQueueRef() {}
+
 private:
 	void				flush();