Fixed #100: Display topic setter and creation time

Fix for #100

The setter is provided by node-irc as both nick and message.args[2].
The creation time is provided by node-irc as a unix timestamp in message.args[3].

I'm not sure if the timestamp format I've used here [display.timestamp in Komanda.settings] is the best one for this message, but that would be trivial to modify later.