Now we use the browser's native dblclick event on pointer
devices, and we fire dragstart and dragend only if we're really
dragging, and not on mousedown/touchstart and mouseup/touchend.
We don't register two listeners for mouseup and touchend any
more. And instead of using the native click event on touch
devices, we react on touchend, to make clicking more responsive.
On pointer devices, the underlying native event of a dblclick
event is now a click event.
ol.overlay.Overlay can be used to bind DOM elements to a
coordinate on the map. It has positioning options to support
e.g. popups or image markers that have an anchor at the bottom
and an unknown size.
The overlayContainer stops propagation on mousedown and
touchstart events, so clicks and gestures on overlays don't
trigger any MapBrowserEvent. To make this work reliably, we now
only fire dblclick in mapbrowserevent.js when there was a
previous mousedown or touchstart. The default container for
controls is now the overlayContainer.
By handling click, dblckick and drag sequences in MapBrowserEvent, we can overcome closure issues with touch events. In particular, these issues were double drag events (from mousemove and touchmove) and a missing dblclick event on touch devices.
