Object Viewer 7.2 Enhance: semi-persistent object tabs; close slots too? query [2]
Bug Number: n/a
Release notes (y/n): No, not this detail.
For Release Nums: 7.2

FIX to "Close Slots Too?" query dialog use from the closeEvent() method.
In the case where this event was generated by clicking the window's titlebar
RED-X button and the user selects CANCEL from the "Close Slots Too?" popup 
dialog, we were aborting the QCloseEvent incorrectly -- calling "accept" when 
we needed to call "ignore".  See change in method: 
  OpenObjectDlg::closeEvent (QCloseEvent*).

Also, improvement in the "Close Slots Too?" dialog's default button.
It had always been "No" before.  But it would be better to default to the 
PRIOR ANSWER (Yes or No) indicated by the user.

Also, FWIW, added the following static method (but not yet used), in case 
we would like to allow the showing of the "Close Slots Too?" query dialog 
AFTER a model clear (so also, after loading a different model).

   static void allowShowAgain() { _dontShowAgain = false; }