* New primitives `terminal-get-state' and `terminal-set-state' allow

* New primitives `terminal-get-state' and `terminal-set-state' allow
  Scheme programs to get an object representing a terminal's state
  structure, and to restore the terminal's state from such an object.

* When Scheme is terminated, restore the control terminal state.
  Previously this was done only when suspending Scheme.

* On machines that have it, disable `t_dsuspc' (the delayed suspend
  character).  Save this and any other TIOCGLTC state in the terminal
  state structure.  Previously POSIX machines ignored this state even
  if it was present.