Volunteer shift signups are working again

I've made some changes to how we do Angular now that I have an extra year of Angular experience and have a better idea of how to write idiomatic and testable Angular code.  (Still no Angular unit tests for the signups code, but at least we could easily write some now, whereas before it was out of the question.)

I'll leave a bunch of inline comments explaining what I did.
Do you mean, what's the proper ticket to discuss configuration in general in?  We don't really have one right now.

I understand that the Anthrocon folks would like to move a lot of our configuration out of flatfiles and into the database.  If that's what you mean, I'd open a ticket for it, and that would be a good place for that discussion.

A high level summary of my own feelings on that issue: I don't have any ideological preference, but I think in practice keeping most of our config in flatfiles leads to cleaner code, with the downside that it's less administratable at runtime.  So we're basically exchanging slightly cleaner code (in my guesstimate/opinion) for having the system's configuration be more opaque to people with admin access.  I don't feel all that strongly one way or the other, but my general sentiment is pro-flatfile.  I'm happy to discuss specifics in more detail in some ticket specifically about this, though.