Splitting restore/saveState() to separate functions for dockwidgets and toolbars

If restore/saveState() is separated into separate functions for saving/restore dockwidgets and toolbars, it allows users to have a finer control on their application and implement something like Visual Studio's design for restoring. Visual Studio will keep the toolbars where they are and restore the dock widgets when it opens a new solution, separating the save/restore functions will aid the user to implement this.