Rails 3: jquery_tokininput railcast #258 - how to add new entries?

Hi I've followed ryan bates railscast on the jquery_tokeninput gem and I've gotten everything wor开发者_开发技巧king on my app except the ability to create new entries. From the show comments it looks like an issue was started and people have been able to figure out a way to do this. https://github.com/loopj/jquery-tokeninput/issues#issue/11

Can someone please help explain what I need to add to get this working?