only look up rpchandler for node if we have nodeid

fix some comments and nomad monitor -h output

command/agent/command.go

@@ -382,7 +382,6 @@ func (c *Command) setupLoggers(config *Config) (*gatedwriter.Writer, io.Writer)
 		Writer: &cli.UiWriter{Ui: c.Ui},
 	}
 
-	// TODO can this be killed
 	c.logFilter = LevelFilter()
 	c.logFilter.MinLevel = logutils.LogLevel(strings.ToUpper(config.LogLevel))
 	c.logFilter.Writer = logGate