js/jquery：script src方式引入js文件实现异步加载功能
<script src="js/require.js" defer async="true"></script>
async="true" 针对于非IE浏览器，defer实现IE浏览器的异步
<script src="js/require.js" defer async="true"></script>
async="true" 针对于非IE浏览器，defer实现IE浏览器的异步
