TODO

  * implement caching using x-modified-since for fetch paginated
  * put the invite link straight in peoples profiles

  * have an end stage / flash sale thing at the end when the algo is too slow

 • wya to do first round of +1 easier: just block off half the quota?   
  * waiting list: send voucher for all products

  * membership card
  * child membership card

  * add SMEP and directed transfers to tool
  * test transfers

# nice to have 
  * human readable log display
  * add settings - nav_event_settings
  * make transfer allowed configurable
  * make a PretixResponse object to paginate (with e.g. .first(), .all())
  * move tool things to pretix tasks
  * split out features useful for others into their own plugins
  * a way for group leads to directly email volunteer groups based on questions

User stories
  * Register for lottery
  * Buy a membership
  * Invite a friend
  * Refund membership
  * Transfer memberships
  * Get volunteers to contact for clowns/perimeter/etc 
  * Get demographics for survey weighting


NExt year
  * send a link to change reg details