change the TS, notifying local users of this but not servers (note that
ban-like modes remain intact; invites may or may not be cleared).
+A JOIN is propagated with the new TS of the channel.
+
KICK
source: any
parameters: channel, target user, opt. reason
split riding may happen: if the key (+k) differs or the incoming simple modes
include +i, kick all local users, sending KICK messages to servers.
+An SJOIN is propagated with the new TS and modes of the channel. The statuses
+are propagated if and only if they were accepted.
+
SJOIN must be used to propagate channel creation and in netbursts. For regular
users joining channels, JOIN must be used. Pseudoservers may use SJOIN to join
a user with ops.