try to fix twice change event(one is original event,and the other one is triggered by plugin)

there is twice change event,one is original event,and the other one is triggered by plugin.
when use ajax on change event,twice chang event will be problem
move lamdba out to delete the trigger will be help.
worked on demo.
http://root.gpgkd906.com/jquery_chained/demo.html

sorry for poor english,and like your plugin