Buflines need to know which part of text to wrap with the timestamp. The
second parameter to `AddLine` (and shorthands) is that text, which after
wrapping is added as the `text` parameter to `NamedFormat`.
Timestamps are formatted at the moment buffers are flushed to the
client. The client parameter to `GetLine` provides access to the User
and the new server-time capability.
This fixes a bug where an unauthed IRC connection will cause your
clients nick to be the default nick. But this is before we update
the client to use this nick. If a client tried another nick when
connecting then they are still expecting this nick.
