Implement automatic channel joining

Avoid the need for an administrator to join the bot to channels by
implementing a configuration option allowing the passing of channels
the bot should always join to by itself upon startup.

Signed-off-by: Georg Pfuetzenreuter <mail@georg-pfuetzenreuter.net>

wat/bot.go

@@ -39,7 +39,7 @@ func CleanNick(nick string) string {
 
 func PrefixChannel(channel string) string {
 	// there could theoretically be other channel prefixes ..
-	if channel[0] != '#' || channel[0] != '!' {
+	if channel[0] != '#' && channel[0] != '!' {
 		channel = "#" + channel
 	}
 	return channel