Better use of good.dom.createDom in zoom slider
Simplify zoom slider code
Fix issue where map is stuck in drag mode

If the control container stops "up" events the map browser event handler won't see these events and will keep triggering "drag" events.
Do not pretend the zoom slider supports touch
Change ol.control.ZoomSlider#amountDragged_ signature
Handle click on zoom slider
Stop clicks on zoom slider thumb
Merge pull request #1285 from elemoine/clik_zoomslider

Handle click on the zoom slider