Ensure that widgets dragged into other sidebars stick
Update semantics of toggleActive() method to not also change active state

The toggle() method is now known as toggleActive(), and it does not change the state but
merely is a handler to respond to a state change. The same goes for toggleExpanded() in
relation to the expanded state. This eliminates the onExpanded/onCollapsed, onActivated/onDeactivagted

Add some todos