cck_signup 6.x-1.0-alpha4

- #931972 by jhedstrom: Capacity not checked on signup
- #1015814 by jhedstrom: Error when a Node Reference has no content types that can be referenced.
- Comment cleanup and some better logic for picking fields on the admin interfaces.
- Changing event-dates token description to specifiy which date format will be used.
- #945402 by jhedstrom: Fixed Reminder notifications are still sent after a signup has been deleted.
- Allowing interval for e-mail notifications to be changed on a per-node-type basis.
- Tweak to js for expanding group data form elements.