Confirm closing the Window with existing count

[ABC]

I occasionally closed the window with multiple timeframes and counts in it. Fortunately I was able to recover it, but otherwise large piece of work would have gone from one single click. It would be nice if there were a conformation comming "Do you really want to close it?" if the window contains any objects in it. No need to confirm close of masterchart.

[Christian]

Comes with version 21.1