store the permissions in an object in the collection
store the permissions in an object in the collection

That way we can have multiple permissions for each user/instance
relationship

mysociety/popit,Sinar/popit,mysociety/popit,Sinar/popit,openstate/popit,mysociety/popit,openstate/popit,Sinar/popit,Sinar/popit,mysociety/popit,openstate/popit,openstate/popit,mysociety/popit