http://www.phperz.com/article/15/0109/45586.html
http://www.360doc.com/content/14/0718/18/21412_395329347.shtml
http://www.5imoban.net/jiaocheng/bootstrap/2015/1119/1484.html
http://web.gxzj.com.cn/News.aspx?id=230795
兼容IE8使用
http://www.mamicode.com/info-detail-503562.html
http://www.ijophy.com/2014/05/bootstrap3-compatible-with-ie8.html