Now we can just control lower selector with mouse/touch - this adds logic to guess which selector we want to control (based on distance between touch/mouse click point and lower/upper selectors).
We want to guess selector only when we start dragging or when we do single mouse click. Also when we are dragging selector we need to swap current selector in case we dragged lower selector behind upper selector and vice versa.
slider control: manipulate selector that is closer to clicked/touched…
Looks good to me.
i'd consider this a bugfix as it's a new feature...