add -version option to display version and quit

--HG--
branch : nmdc-ircfrontend

main.go

@@ -33,9 +33,15 @@ func main() {
 	hubsec := flag.String("hubsecurity", "Hub-Security", "Nick used for administrative events")
 	verbose := flag.Bool("verbose", false, "Display debugging information")
 	autojoin := flag.Bool("autojoin", true, "Automatically join clients to the channel")
+	version := flag.Bool("version", false, "Display version and exit")
 
 	flag.Parse()
 
+	if *version {
+		log.Printf("%s version %s\n", APP_NAME, APP_VERSION)
+		return
+	}
+
 	log.Printf("Listening on '%s'...", *ircAddress)
 	if *autojoin {
 		log.Printf("Clients will be automatically joined to the channel.")