This allows using browser back and forward buttons
once users have started heading between revisions.
This also updates the URL so that the page can be
reloaded at any time and the same state will be held.
(This also removes a commented out block of code that
I think was left for updating the URL)
Change-Id: I4cfe38f76eeb9e090f0a8a42e22e75cf84014d60