…up, rather than INADDR_ANY, as joining the group is not restricted to the socket (but binding is). Also add linger settings to zmq sockets

…default to the same port)

ServiceDiscovery: add continue such that when there are messages available from the inproc socket, they are all processed before moving to broadcast part. Otherwise this means at most one message is processed per SD broadcast period.
Services: add lifetime argument. conversion from unix ms to time string now done on client not MM. some DB field renames, remove quotes around embedded JSON. Responses with version numbers are just the number, no longer JSON, for reduced traffic. Get requests use SQL directly with json_build_object to have Postgres form JSON directly. Remove option to retrieve timestamp with GetRootPlot and GetPlotlyPlot for simplicity.
ServicesBackend: make counters atomic. Update port advertisement methods.