Save date_of_birth to person on registration

See merge request !77

Update link to email

See merge request !76

feat: Duplicate form for account registration

See merge request !75

Resolve "Update outdated link"

Closes #73

See merge request !74

Resolve "Fix optional/additional field handling after editing event"

Closes #72

See merge request !73

Resolve "Fix initial data getting for school details"

Closes #71

See merge request !72

Merge branch '66-make-required-ness-of-contact-data-e-g-address-configurable-per-event' into 'master'

Resolve "Make required-ness of contact data (e.g. address) configurable per event"

Closes #66

See merge request !71

Resolve "Skip payment step when costs are 0 for an event"

Closes #68

See merge request !70

Resolve ""title" field of additional fields CRUD list causes name collision"

Closes #69

See merge request !69

Resolve "Migrations fail"

Closes #67 and #65

See merge request !68