* Initialize termios struct before using it, from the current tty settings.
* Set speed earlier. (This, combined with the above, was causing DTR to be
dropped briefly on startup.)
* Add `-m' option to avoid using HUPCL.
Also:
* Remove findspeed() altogether, as we don't need it and it's ugly.
* Use tcgetattr() and tcsetattr() rather than TIOCGETA and TIOCSETA. The
former is POSIX; the latter is not.
