Return the number of pixels an element can be scrolled by in all directions
canScroll(element) will recurse up the DOM tree of an element and add up the scrollable distance on all of its offsetParents
canScroll(someElement);
// -> {up: 10, down: 20, left: 0, right: 0}
If you only care about the scrollability of the target element, you can use canScroll.canScrollSelf(element), which does not recurse.