/* $DOC$
   $NAME$
      ft_SInkey()
   $CATEGORY$
      Keyboard/Mouse
   $ONELINER$
      Replacement for Inkey() that tests for SET KEY procedures
   $SYNTAX$
      ft_SInkey( [ <nWaitTime> ] ) -> nKey
   $ARGUMENTS$
      <nWaitTime> is the number of seconds to wait.  If zero,
      ft_SInkey() will wait indefinitely for a keypress.  If not
      passed, ft_SInkey() does not wait for a keypress.  If NIL,
      it is treated the same as 0.
   $RETURNS$
      The Inkey() value of the key pressed.
   $DESCRIPTION$
      ft_SInkey() is similar to the function provided by Nantucket in
      keyboard.prg, with one significant difference: you can pass NIL
      to Inkey(), which will be treated as a zero (i.e., wait indefinitely
      for keypress).  Therefore, it is necessary to differentiate between
      an explicit NIL and one that is a result of a formal parameter NOT
      being received.

      ft_SInkey() differs from the standard Inkey() in that it will
      respond to any keys set with SET KEY TO or SetKey().
   $EXAMPLES$
      SetKey( K_F1, {| n, l, r | HELP( n, l, r ) } )
      ? ft_SInkey( 0 )       // HELP() will be called if F1 pressed
   $END$
 */