wait_for_int (itype.i2.r, row.i2.r, col.i2.r, nsecs.i4.v)
	This routine will flush any non-empty I/O buffers and wait 'nsecs'
	seconds for the next keyboard or terminate interrupt.  When a
	keyboard interrupt is detected, a terminate interrupt is detected,
	or the timeout expires, control will be returned to the caller.
	(If 'nsecs' is <= 0, the routine will never timeout.) 'itype', 'row',
	and 'col' will be set to the interrupt type, cursor row and cursor
	column (from the INTYPE routine).

	itype		returned interrupt type (constants are in cnsparam)
	row, col	returned interrupt location
	nsecs		number of seconds to wait

	This function requires the following include files:

	cnsparam_h, cbslib_h

	Related functions:

	repeat_kbd_intype, window_intype, intype