keep page context (tabs) when moving from page to page

[saracarl]

Dr. Lee at Princeton suggested this:

One suggestion is to allow us to go to the next page from the tabs we’re using. So, if I’m using the translate tab, I’d like to be able to move back and forth on the tab and not be taken back to the transcription tab and then take the extra step to find the page.

and I think it's a great idea.