Think about how we could have CMS keep the data on RWS up-to-date

As outlined in many points (mainly in the documentation for RWS) there's no way for CMS to update or delete the data on RWS other than (deleting it on RWS and) restarting SS.

I can't see easy solutions to this problems. We can either add a call to a function that updates RWSs each time we modify some data on the DB (it's a hard work, and it's easy to forget something, now and in the future). Or we could periodically check the database to see if something changed and, in that case, trigger a re-send to RWS (we cannot re-send without checking (and rely on the over-writing mechanism) because this doesn't allow us to detect deletions).

Another approach would be to use the same asynchronous notifications I proposed in #106. Sure, this would make us definitely PostgreSQL-dependent, as there is no easy "fallback" (as we have with the cacher).