参考资料 http://www.cnblogs.com/Darren_code/archive/2011/12/31/property.html
http://www.cnblogs.com/nonsuch/archive/2010/06/23/1763471.html
http://www.cnblogs.com/nonsuch/archive/2010/06/23/1763363.html
http://www.cnblogs.com/tugenhua0707/p/3354259.html
http://www.cnblogs.com/yexiaochai/p/3759959.html
http://www.cnblogs.com/zhengyun_ustc/archive/2013/05/09/frontendoptimize.html
http://www.cnblogs.com/developersupport/p/webpage-performance-best-practices.html
http://www.cnblogs.com/sprying/p/4251682.html
http://www.cnblogs.com/ToNi/p/4451594.html
http://www.cnblogs.com/dojo-lzz/p/4591446.html