code: function _addEvent(el, type, handler, capturing) {
    el.addEventListener(type, handler, !!capturing);
  }
docs: Attach event in a cross-browser fashion
  @static
  @param {DOMElement} el DOM element to which to attach the event
  @param {String} type The DOM event (without 'on') to attach to the element
  @param {Function} handler The event handler to attach to the element
  @param {Boolean} [capturing] Whether or not the event should be
  capturing (W3C-browsers only); default is false; NOT IN USE