* ports.c (flush_void_port): renamed to flush_port_default.

	* ports.c (flush_void_port): renamed to flush_port_default.
	(end_input_void_port): renamed to end_input_default.

	* init.c (scm_standard_stream_to_port): create a void port instead
	of opening /dev/null if the standard file descriptors are bad.
	advantages: no portability problems, doesn't waste a file descriptor,
	simplifies the code (thanks to Marius for the idea).

	* vports.c (s_scm_make_soft_port): call scm_port_non_buffer.

	* void ports: make reading from a void port give EOF instead of
	segv:
	* ports.c (s_scm_sys_make_void_port): modified docstring.
	(fill_input_void_port): new proc.
	(scm_init_ports): set up fill_input_void_port.
	* ports.c (scm_port_non_buffer): new proc.
	(scm_void_port): call scm_port_non_buffer.

	* fports.c (scm_setvbuf): docstring: remove the fcntl documentation
	which was incorrectly appended.