Port ui.js to React?

[jfly]

Matteo Colombo just ran into a bug where rounds disappear as he's adding rounds.

I was able to debug this for a little while with him, and it appears to be related to our hashchange listener. When I comment out the hashchange listener, the problem goes away for him. What appears to be happening is that the hashchange event is firing at unexpected times, which causes us to go into this branch: https://github.com/cubing/tnoodle/blob/c6c0f6650e10d4ae76467532deb19a2504de9b67/scrambler-interface/WebContent/scrambler-interface/js/ui.js#L1096-L1100, which causes us to reset the DOM elements.

The code as currently written is very hard to reason about, and that's because we don't have an explicit model. Porting to react would be a good way of forcing us to have an explicit data model that just needs to stay in sync with the url.

Using React would force us to add another build step (compiling jsx to js), but I'd personally be okay with using the in browser jsx -> js compiler just to get things going. Performance isn't critical here.

[MatteoColombo]

If someone is interested, here is the video i made to show the problem:
https://www.youtube.com/watch?v=xpD9CMQKShM

[jfly]

We have a new, React based UI in #236, so I'm going to close this issue.