gpress event to Elm so we start hinting
         *   - add a touchmove listener
         *     - on touchmove, tell Elm which element is currently under the finger
         *   - add a touchend listener so we can stop hinting regardless of where we are in the page
         *
         * How this makes it scroll friendly: preventDefault on touchmove is only triggered after
         * the longpress, so simple swipes up and down are not affected.
         */
        function handleTouchStartScrollFriendly(id) {