Register uuid / configName / humanReadableName for each client

Several details worth discussing here but patch shows the broad outline.

 - uuid, generated client-side so the client has it without an
   extra round trip
 - configName, an ID we could use to recognize "the same" client
   and do things like save per-client configuration
 - humanReadableName, we might use to display which client
   triggered a certain task or things like that