* Move the printf() delay to just after the printf(), where it actually makes
sense.
* Use zstty_stint() and zstty_softint() from zsparam(), to force an immediate
update of the carrier and flow control status. Abuse this in the attach and
open functions to defer all of that work. This insures that we don't lose
any status updates.
* Don't screw with register 1 when closing the console.
* Fix bugs in TIOCM??? (stay semicolon, clearing DTR while transmitting).
* Add comments in a couple of places.