All users of the hostname updated to get it from the isc_scb.

(login_old): Set login_time, not connect_time.
(login): Ditto.
(logout): Use login_time, not connect_time.
(who_is_on): Removed dead code.
(who_is_on_ident): Ditto.
(who_is_on_dynamic): Removed dead code.  Don't include sessions
	until the handshake is completed.
(get_session_info): Don't include sessions until the handshake is
	completed.
(get_session_info): Use connect_time, not login_time, as the
	connection_time.
(get_static_session_info): Don't include sessions until the
	handshake is completed.  Use connect_time, not login_time, as
	the connection_time.
(get_session_info_ident): Ditto.
(disconnect): Don't include sessions until the handshake is
	completed.
(get_client_name): Ditto.
(get_client_version): Ditto.