web UI now uses modules, and relies less on bodge to make things work.
Also fixes an issue where invites where "failed to send to xx" appeared
in invite form.
i wanted to split up the web ui components into multiple files, and
figured it'd be a good chance to try out typescript. run make typescript
to compile everything in ts/ and put it in data/static/.
This is less of a rewrite and more of a refactoring, most of it still
works the same but bits have been cleaned up too.
Remaining javascript found in setup.js and form.html