Staff users just see their events

[nukeador]

Staff users just have to see the events they created and just the registration of the events they created.

http://reinout.vanrees.org/weblog/2011/09/30/django-admin-filtering.html

We'll need and extra "owner" field on events

[nukeador]

Also keep in mind that we have a group for people who checks-in people at the event and need to modify registrations, should that role see all registrations? In this case should the owner be in charge of the check-ins?

[nukeador]

Probably having just one person being able to see an event registrations is a bad idea, user groups should be the way to go, but it involves more work/changes.