Nodejs异步
http://cnodejs.org/topic/4f16442ccae1f4aa2700113b
http://cnodejs.org/topic/4f16442ccae1f4aa27001123
http://www.infoq.com/cn/news/2011/09/nodejs-async-code
http://repository.jscex.info/master/samples/async/sorting-animations.html
http://cnodejs.org/topic/4f50dd9798766f5a610b808a
出处:http://cnblogs.com/daishuguang