Qt Viewer now copes with deleted objects.
Qt Viewer now copes with deleted objects.

daviddeng/azrael,olitheolix/azrael,daviddeng/azrael,olitheolix/azrael,olitheolix/azrael,daviddeng/azrael,olitheolix/azrael,daviddeng/azrael,daviddeng/azrael,olitheolix/azrael