* 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.