Add click event as responsive alternative to singleclick

The `singleclick` event makes the application feel slow because of the 250 ms delay that is used to rule out a `dblclick`.

This `click` event has the advantage that - unlike the DOM `click` event - it is only fired when no dragging occurs between pointer down and up. With the addition of this event, app developers have the choice of caring about 'double' or 'single', or just a responsive click.