jQuery--Promise object
http://blog.mediumequalsmessage.com/promise-deferred-objects-in-javascript-pt2-practical-use
http://blog.mediumequalsmessage.com/promise-deferred-objects-in-javascript-pt1-theory-and-semantics
http://msdn.microsoft.com/en-us/magazine/gg723713.aspx
http://yue.st/slides/deferred/#title-slide
http://www.douban.com/note/219529013/
http://www.cnblogs.com/lhb25/archive/2013/03/05/jquery-deferred-promise.html
http://www.cnblogs.com/aaronjs/p/3342344.html
http://www.blogjava.net/javagrass/archive/2011/07/19/354584.html
http://jqfundamentals.com/chapter/ajax-deferreds
http://news.cnblogs.com/n/192726/
http://javascript-jedi.com/category/jquery/
http://kb.cnblogs.com/page/191787/
出处:http://cnblogs.com/daishuguang