Add -debug command line flag

irc.go

 	"strings"
 )
 
-func (i *IRCCat) connectIRC() error {
+func (i *IRCCat) connectIRC(debug bool) error {
 	irccon := irc.IRC(viper.GetString("irc.nick"), viper.GetString("irc.realname"))
 	i.irc = irccon
+
+	irccon.Debug = debug
 	irccon.RequestCaps = []string{"away-notify", "account-notify", "draft/message-tags-0.2"}
 	irccon.UseTLS = viper.GetBool("irc.tls")
+
 	if viper.IsSet("irc.sasl_pass") && viper.GetString("irc.sasl_pass") != "" {
 		if viper.IsSet("irc.sasl_login") && viper.GetString("irc.sasl_login") != "" {
 			irccon.SASLLogin = viper.GetString("irc.sasl_login")
 		irccon.SASLPassword = viper.GetString("irc.sasl_pass")
 		irccon.UseSASL = true
 	}
+
 	if viper.GetBool("irc.tls_skip_verify") {
 		irccon.TLSConfig = &tls.Config{InsecureSkipVerify: true}
 	}

main.go

 package main
 
 import (
+	"flag"
 	"fmt"
 	"github.com/deckarep/golang-set"
 	"github.com/fsnotify/fsnotify"
 }
 
 func main() {
+	debug := flag.Bool("debug", false, "Print raw IRC lines")
+	flag.Parse()
+
 	loggo.ConfigureLoggers("<root>=INFO")
 	log.Infof("IRCCat %s (%s) starting...", branch, revision)
 	viper.SetConfigName("irccat")
 		return
 	}
 
-	err = irccat.connectIRC()
+	err = irccat.connectIRC(*debug)
 
 	if err != nil {
 		log.Criticalf("Error connecting to IRC server: %s", err)