Closes#294. Closes#304. This renames the "nick" field to "sender", and "identhost" to "sender_identhost", to be less ambiguous when a message sender is a server.
Some of the logic was inverted so that the Clientbot would try to kick invalid things like GLolol/ovd, and send clientbot KICK payloads when it's supposed to forward an actual kick.
This also fixes KICKs from servers not being relayed by clientbot.