code: function getOuterHeight(el, defaultValue) {
      var height = this.getHeight(el, defaultValue);
      var bTop = parseFloat(this.getStyle(el, 'borderTopWidth')) || 0;
      var pTop = parseFloat(this.getStyle(el, 'paddingTop')) || 0;
      var pBottom = parseFloat(this.getStyle(el, 'paddingBottom')) || 0;
      var bBottom = parseFloat(this.getStyle(el, 'borderBottomWidth')) || 0;
      return height + bTop + bBottom + pTop + pBottom;
    }
docs: 获取外层高度
  @param  {HTMLElement} el dom节点
  @param  {Number} defaultValue 默认值
  @return {Number} 高度