serversay() calls add_last_type(), so there's no need for the callers to do so
as well.
Remove the first argument to serversay() because it was always called with 1
anyway.
We don't know the server's proper name until registration, so the test against
that isn't reliable. We shouldn't be able to receive messages from anyone else
until we're registered, so this should be safe.
This requires changing serversay() to accept the from name instead of the
from_server. While we're there, replace the use of alloca() with simpler
logic based on m_sprintf().
