Admin import of event attendees

[tdfischer]

It is currently unclear how to mark someone as having attended an event in the UI, either through import or through searching by E-Mail address.

As an organizer, I would like to use the CSV import for either marking people as attended an event for tracking purposes, or as importing an e-mail list subscriber.

Importing the later can be hacked around using tags in import spreadsheets, but there currently is no way to check someone in outside of them being logged in and doing it; there is no paper backup, and no way to have a check-in form open on a public laptop.

EBFE currently tracks this using Typeform; one form is for the public access netbook, the other is for typing up sign-in sheets to a digital format.