usablica/intro.js — pull request #221 by dswen (2013-11-18 03:30:44+00:00)
Title: Add checkpoints to intro.js

Enable programmer to define which steps are checkpoints. I.e.
prevent the user from going back after certain steps. This is
useful if the user will be changing the state of the system
(creating a database entry, etc.) so the user doesn't go
back and redo their change.