-RM-3646-MR-Backup access
As a regular 2FA user temporarily unable to use my second factor,
I want to be granted a fallback access for a limited period of time,
so that I can access SPs requiring 2FA.
→ process independent of Shibboleth (helpdesk-provided OTP)
(from redmine: issue id 3646, created on 2016-04-13)