Use sisyphus.js to store review draft

[Gregoire Detrez]

Sisyphus.js is a javascript library that stores form data in the browser until the form is submitted, so that if you close the browser, open a new tab or accidentally get logged out, you can recover what you entered.

In our case it would allow to scrape all the server-side code that deals with review drafts and simplify the js code as well.

[Evgeny Kotelnikov]

I guess the question is whether we want client-side or server-side drafts. Server-side draft have the advantage of being accessible from different browsers/computers and shared among graders. I personally have used the latter a few times, although I would agree that these might not be very common use cases. I wouldn't say that the amount of server-side code dealing with drafts is excessive.

[Gregoire Detrez]

@aztek if you think it's worth it, I'm happy to let it be.