close and open actions for plain opening and closing the tickets
respond_with so fields are not cleared on invalid update

the custom actions are not strictly restful. But adding a subresource felt like too much overhead and is conceptually hard to grasp (so we destroy the openess of the ticket to close it?).

This controller does too much - so the tests are also getting large and hard to keep track of

Ticket.is_creator_vlidated? now actually fetches the user from the db and returns false if it does not exist.

Also renamed help to support so it's harder to confuse it with documentation