Persist toolbar and status bar configuration

[curtis]

The main Swing application's JToolBar can be detached into a floating window, or docked to any of the top, left or right edges of the application window. We currently persist the last XY position of the application window, but not the orientation of the toolbar, nor whether it is detached into a separate window. We should do this, so that users do not have to reconfigure the toolbar every time ImageJ2 starts up.