remove QWidget from worker interface
pass simple widget to host GUI
adding simple widget above mesages tab widget & complex widget as 'App' tab
adding simple widget and complex widget to the launcher from worker
Connect to MainWindow::destroyed instead of custom close_sig slot and set QT::WA_DeleteOnClose attribute to true so that calling delete in the close_sig connected slot does not destroy in the wrong sequence for the widget. This fixes crashes when the menu was used to close the widget.