New interesting demo available

[MJS@mjs.us]

I've refactored one of my apps to take advantage of the new back button functionality.  With PostRedirectGet = prgEnabled it seems to mostly work but for two issues:

1. RegisterCallBack functions fail if invoked after a back button, forward button sequence.  They will only work again after a full refresh.
   
2. Back / forward history gets lost after a bootstrap modal dialog popup (pure bootstrap, no IW bootstrap components).  Not worried about this one so much.
   

I'll provide a demo for issue 1 after some more research.  I have a strong interest in seeing this new functionality work 100% as IW back button behavior always requires an explanation to the customer.  If this gets implemented 100% it would be the 3rd best all-time enhancement of IW in my opinion.