X M,C,S works - cluster could start and client connected and could get pt and nodetab from M; attach to S and read all objects from there; yay!

X tracing: Fix bug when probe detach did not work (its .prev was nil so no way to modify original probe list)

Else M has to listen from incoming connections from S but currently to
simplify workings it does CloseAccept after accepting S's identification.

It also looks logical from protocol point of view that there is a reply
to StartOperation command.