As the space Owner, I can decide which Things can have Conversations

(User Story, To be Fixed , Priority: Low, Test Status: No automated tests yet , Reported By Justin du Coeur, )
Conversations
Summary: Querki's default is to allow Conversations on all Things. However, there should be an explicit flag to disable / enable Conversations. As usual, it should be possible to set this on an individual Thing, on a Model (so it applies to all Instances), and on the Space (so it applies to all Things in this Space).