* fhandler.h (class fhandler_pipe): Remove members writepipe_exists,

	* fhandler.h (class fhandler_pipe): Remove members writepipe_exists,
	orig_pid and id.  Make hit_eof inline.
	* fhandler_fifo.cc (fhandler_fifo::open): Drop handling of
	writepipe_exists, orig_pid and id.
	* pipe.cc: Ditto throughout.
	(pipecount): Remove.
	(pipeid_fmt): Remove.
	(fhandler_pipe::hit_eof): Simplify.  Move to fhandler.h.
	(fhandler_pipe::dup): Drop leave label.
	(fhandler_pipe::create): Drop has_unreliable_pipes case.
	* wincap.cc: Remove has_unreliable_pipes throughout.
	* wincap.h: Ditto.