Currently, if a master's name is specified using the --master switch, testclient blocks until the UUID of the name is resolved via a Directory People Search, to ensure that it is an agent. This patch changes that behavior. If --master is used to specify a master by name, objects are explicitly ignored. The master's key is resolved asynchronously, so that commands that rely on MasterKey's presence continue to work. This results in a much faster startup time for testclient.