authorized_keys needs to be managed

it appears that there is no puppet recipe to set authorized keys, so we still rely on leap node init for this. that means when adding, or removing a user, the admin needs to do a node init, which is not correct

hiera files already include a ssh.authorized_key definition, this should be put in /root/.ssh/authorized_keys by puppet during a deploy

perhaps a tag can be added so that an admin can do a deploy to add a user and remove a user without having to do a lot of things

(from redmine: created on 2013-04-12, closed on 2013-06-26, duplicates #3760 (closed))