Fix: Use 2014 date on 'full' page
Fix: RSVP: Work with 0 reservations

The code to get the roles count was broken when
there were 0 reservations in the system.
RSVP: Save timestamp with reservation

It can be useful to know when people registered,
like when tracking the rate at which people are
signing up.
RSVP: Add page for food preferences

Allow guests to specify a preferred diet and
food allergies.
RSVP: Clarify payment text

Ask people to add their name to the envelope
when they pay in cash, and be a little less
lax with our "pay when you want" message.
RSVP: Turn on reservations

Open up registration, with a cap at 150.
Database: Allow getting guest data by id

As we allow guests to edit their data, we need
a way for them to first get access to it.