Restored aaron's magic import which works somehow
Move things from lib/ back into backend/ to unbreak the tests. 'Twas a
silly idea.
Add fields to pledge form, and subscribe people who pledge (opt-out).

Adds email, first and last name, and an option to sign up for
email. The frontend sends a superset of everything it sent before, and
the backend expects, but doesn't require the new fields, so there
(hopefully) shouldn't be any cutover issues.