Send a reply to RegisterClientRequest
factor out reply-with-error and exception for client registration
When client socket closes, complete any outstanding promises
Wait for registration reply in client before proceeding

The important thing here is really printing out any ErrorResponse
Validate configName and humanReadableName
SimpleConnector: write match on replyTo in simpler way
Merge pull request #78 from sbt/wip/havocp-client-name-validation

validate client-provided names