The changes haven't been merged into BitAddress.org, ... and I don't know that anyone has vetted the entire source with that change from the Zeilapp GitHub repo.   So that's why I wrote "probably isn't ready for prime time".   

But if you want to try it out, save the .html from Zielap's repo to a local directory and open it in your browser.  But you might not want to trust it with too much mBTCs without ensuring it can be trusted.   
 - https://github.com/Zeilap/bitaddress.org