Function clone

Sortable.js:501–511

(el)

    el.scrollTop += y;
  }
  function clone(el) {
    var Polymer = window.Polymer;
    var $ = window.jQuery || window.Zepto;
    if (Polymer && Polymer.dom) {
      return Polymer.dom(el).cloneNode(true);
    } else if ($) {
      return $(el).clone(true)[0];
    } else {
      return el.cloneNode(true);
    }
  }
  function setRect(el, rect) {
    css(el, 'position', 'absolute');
    css(el, 'top', rect.top);