When quitting the app, director init is called again

[imtrobin]

Reporting that when app is quitting, certain sequences causes the Director to be recreated again

E.g in win32, onGLWMouseMoveCallback, it calls Director::getInstance ()->geteventDispatcher, after Director dtor is already called, resultin in a new instance.

Repro:

1. Have a quit button in the scene that calls Director end (e.g. Helloworld)
2. Click the button and move the mouse at same time.

https://filedn.com/l3TGy7Y83c247u0RDYa9fkp/temp/cocos2dx/directordtor.jpg