Missing features

• Notifications
• Invite mechanism
• Restoring userIdent (When a guest looses its userIdent cookie, poll administration becomes impossible)
• Spam protection
• Responsive voting table

Upcoming, breaking changes

• Add UNIQUE constraints to schema (may break, when invalid state already existing)
• Rename “findByPollAndParticipantIdent” to “findOneByPollAndParticipantIdent”