Main points added:
- File Attachments (Agreement only for now)
- Logo to Institution
- Extra ContactTypes
- Subtitle for Contact
- Contact can choose subtitle/kind during activation
- RequestContact
    - Including view/form to submit new request for Partners
    - Including processing view/form for the Admins
- More stuff....

- Edit Institutions
- Edit Partner + Contacts related
- Add Contact

Editorial Administrators are able to reset and resend the verification key
to a person who requested a key. All registrations are shown, so also
old ones. Should this view be extended to have some kind of cleanup function
to periodically remove (specific) old registrations?

Improve logic/code, add possibility to delete UnavailabilityPeriod