We should wrap JSON.parse inside of its own try/catch in case sessionStorage gets corrupted for some unknown reason (we had to battle with sessionStorage issues on FirefoxOS, where sessionStorage would get wiped upon redirection, who knows if other browsers suffer from this too.)..

Crap. sessionStorage being blown away. crap. Will we have to use localStorage and save data into a namespace then save the namespace into both sessionStorage and window.name like we did to save primary info in [FirefoxOS](https://github.com/mozilla/browserid/blob/dev/resources/static/common/js/storage.js#L432-L463)?