* Flush curses support, add new primitives for termcap and terminfo.

* Flush curses support, add new primitives for termcap and terminfo.

* Add new primitives to control terminals:

    TERMINAL-GET-ISPEED
    TERMINAL-GET-OSPEED
    BAUD-INDEX->RATE
    BAUD-RATE->INDEX
    TERMINAL-COOKED-OUTPUT?
    TERMINAL-COOKED-OUTPUT
    TERMINAL-RAW-OUTPUT

* Change X line scrolling so that it does not clear the region that
  the lines are being scrolled out of.  The update optimizer will take
  care of this if it needs to.