As a user, I would like to set a Close datetime for new signups.

[crw]

This is actually a field on the paper Meal Form, upper left:

How I would like this to work:

1. Every meal signup is timestamped.
2. Every meal signup is marked "logged-in" or "anonymous" to distinguish sign-ups that were by authenticated users, i.e. trustworthy signups.
3. Cooks may set an option on the meal form, "Signups After Closed Allowed (true / false)."
4. If a user attempts to sign up after close, and it is allowed, they are allowed to do so with the following caveats:
   1. They are shown an error that says, "You are signing up after close. There is no guarantee that you will have a plate."
   2. Their name is rendered with a big red border around it, and the time of their signup (basically, their place on the waiting list).
   3. If the cooks add any extras, Post-Closed Signups are made "official" on a first-come, first-served basis.