func (bot *Bot) Topic(c, topic string) {
	str := fmt.Sprintf("TOPIC %s :%s", c, topic)
	bot.Send(str)
}
func (bot *Bot) Topic(c, topic string) {
	str := fmt.Sprintf("TOPIC %s :%s", c, topic)
	bot.Send(str)
}
// Topic sets the channel 'c' topic (requires bot has proper permissions)