Attempt to route note.recv when session isn't attached to topic.

On the remaining user operations.

A few fixes to allow running under high load

fix Evict all user's sessions, clear cached data, send notifications …

Also fix logic when it's topic sub request
returns failure (we must skip this topic altogether).

Run clusterWriteLoop on the master topic level.

Remove manual scheduling.

Add a basic sanity test for cluster setup.