QMainWindow/QDockWidget: Add flags to saveState() and saveGeometry to save the current layout.

If the state/layout of a QMainWindow with a QDockWidget in it is loaded at the startup of an application has info on N dockWidgets, regardless of how many dockWidgets you have during the run, the same number of N dockWidgets states/layout will be saved as long as the number of dockWidgets during the run does not exceed N.

If it does exceed N, the number of saved dockWidgets will be N + what number of dockWidgets above N. However if M dockWidgets where created during the run, where M <= N, then the saved state will have info on N dockWidgets where layout of the (N-M) dockWidgets will be reset to zero.

There is not way to only save the state of M dockWidgets and leave out the state/layout of (N-M) that was not created during the time the application was running.

The suggestion is to add a flag to saveState() and saveGeometry() to create a byte array with states/layouts containing only currently existing dockWidgets, or return a byte array with all states/layouts in the QMainWindow.

Currently it will return a byte array with all states that are in the QMainWindow. Some states are loaded and some are from currently existing dockWidgets.