I can change my Notification Preferences and have them take effect immediately

Summary: On the Advanced page, there is a user preference for whether to receive all Comment Notifications in this Space. Problem is, it only takes effect after the Space next reloads.

The issue here is a pure implementation detail: we fill the table of who gets notifications when the SpaceConversationsActor loads, and it doesn't get dynamically updated. The underlying issue is that there is no way yet for UserValue changes to affect it.

The solution seems to be that we need a registry for Ecots to listen to UserValue changes, the way they can for Space changes. They should be able to register their interest in some central Ecot; when we change a UserValue in UserSpaceSession, we go to that registry and publish the changes, the same way we do for Space changes.

Then the ConversationsEcot needs to somehow get the change back to the SpaceConversationActor. I think the implication is that the published event from UserSpaceSession needs to include a pointer to the SpaceRouter, so that the Ecot can loop messages back to the Troupe.