* Eliminate obsolete TTY I/O primitives. These have not been used for

* Eliminate obsolete TTY I/O primitives.  These have not been used for
  several months now.

* If stdin or stdout is a terminal, save its state when entering
  Scheme, and restore it when leaving, as is done with the control
  terminal.  Ignore any attempts to change the state if Scheme is not
  in the foreground.  This code helps prevent buggy Scheme programs
  from screwing up the user's terminal.

* On machines with TERMIOS and BSD_JOB_CONTROL, such as HP-UX, alter
  VSUSPC and t_suspc together.  Altering one and not the other can
  cause the change to be lost.