code: function offEvent(gesture, handler) {
      var gestures = gesture.split(' ');
      Hammer.utils.each(gestures, function(gesture) {
        this.element.removeEventListener(gesture, handler, false);
      }, this);
      return this;
    }
docs: unbind events to the instance
  @param   {String}      gesture
  @param   {Function}    handler
  @returns {Hammer.Instance}