* ports.h (scm_port): make read_pos a pointer to const.

	* ports.h (scm_port): make read_pos a pointer to const.
	strports.c: take care of rw_active and rw_randow.
	fports.c: scm_fport_drain_input: removed.  do it all in ports.c.
	strports.c (scm_mkstrport): check that pos is reasonable.
	ioext.c (scm_ftell, scm_fseek): use lseek.
	(SCM_CLEAR_BUFFERS): macro deleted.
	ioext.c (redirect_port: use ptob fflush, read_flush.
	ports.h (scm_ptobfuns): add ftruncate.
	ports.c (scm_newptob): set ftruncate.
	adjust ptob tables.
*	ports.c (scm_ftruncate): new procedure.
	fports.c (local_ftrunate), strports.c (str_ftruncate): new procs.
	strports.c (st_seek, st_grow_port): new procs.
	fports.h (scm_port): change size types from int to off_t.
	ports.c (scm_init_ports): initialise the seek symbols here
	instead of in ioext.c.
	strports.c (scm_call_with_output_string): start with an empty
	string, so seek and ftruncate can be used.
	* ports.h (scm_ptobfuns): add a read_flush procedure which is the
	equivalent to fflush for the read buffer.
	* ports.c (scm_newptob): set read_flush.
	ports.c (void_port_ptob): set read_flush.
	fports.c (local_read_flush): new proc.  add to ptob.
	strport.c (st_read_flush): likewise.
	vport.c (sf_read_flush): likewise.
	fports.h (struct scm_fport): remove random member.  there's nothing
	left but fdes.  leaving it as a struct to allow for future changes.
	fports.c: replace usage of scm_fport::random with scm_port::rw_random.
	ports.c: (scm_putc, scm_puts, scm_lfwrite): call the read_flush
	ptob proc if the read buffer is filled.
	* fports.h (SCM_FPORT_CLEAR_BUFFERS): rename to SCM_CLEAR_BUFFERS
	and move to ioext.c.
	* fports.h (SCM_MAYBE_DRAIN_INPUT): moved to ports.c.
	use ptob for seek. take ptob instead of fport arg.
	* fports.h (SCM_FDES_RANDOM_P): new macro.  use it in
	scm_fdes_to_port and scm_redirect_port.
	* fports.h (SCM_CLEAR_BUFFERS): new macro.
	* fports.h (SCM_FPORT_FDES): new macro.
	* posix.c (scm_pipe): use fport buffer.
	* unif.c: include fports.h instead of genio.h.
	* fports.c (scm_fdes_wait_for_input, scm_fport_fill_buffer): new
	procedures.
	(local_fgetc): use them.
	(local_ffwrite): use buffer.
	(local_fgets): use buffer.
	(scm_setbuf0): deleted.
	(scm_setvbuf): set the buffer.
	(scm_setfileno): deleted.
	(scm_evict_ports): set fdes directly.
*	(scm_freopen): deleted.  doesn't seem useful in Guile.
	(scm_stdio_to_port): deleted.
	fports.h (struct scm_fport): add shortbuf member to avoid separate
	code for unbuffered ports.
	(SCM_FPORTP, SCM_OPFPORTP, SCM_OPINFPORTP, SCM_OPOUTFPORTP): moved
	from ports.h.
	* fports.c, fports.h (scm_fport_drain_input): new procedure.
	* ports.c (scm_drain_input): call scm_fport_drain_input.
	* scm_fdes_waiting_p: new procedure.
	* fports.c (scm_fdes_to_port): allocate read and/or write buffers.
	(scm_input_waiting_p): check the buffer.
	(local_fgetc, local_fflush, local_fputc): likewise.
	* fports.h (scm_fport): read/write_buf,_pos,_buf_end,,_buf_size:
	new members.
	* init.c (scm_init_standard_ports): pass fdes instead of FILE *.
*	* ports.c (scm_drain_input): new procedure.
	ports.h: prototype.
	* fports.c (FPORT_READ_SAFE, FPORT_WRITE_SAFE, FPORT_ALL_OKAY,
	pre_read, pre_write): removed.
	(local_fputc, local_fputs, local_ffwrite): use write, not stdio.
	(scm_standard_stream_to_port): change first arg from FILE * to
	int fdes.
	(local_fflush): flush fdes, not FILE *.
	* fports.h (SCM_NOFTELL): removed.
	* genio.c, ports.c: don't include filesys.h.
	* genio.c (scm_getc): don't use scm_internal_select if FPORT.
	do it in fports.c:local_fgetc.
	* genio.c: don't use SCM_SYSCALL when calling ptob procedures.
	do it where it's needed in the port smobs.
	* filesys.c (scm_input_waiting_p): moved to fports.c, stdio
	  buffer support removed.  take SCM arg, not FILE *.
	* filesys.h: prototype moved too.
	* fports.c (scm_fdes_to_port): new procedure.
	(local_fgetc): use read not fgetc.
	(local_fclose): use close, not fclose.
	(local_fgets): use read, not fgets
	* fports.h: prototype for scm_fdes_to_port.
	* fports.h (scm_fport): new struct.
	* fports.c (scm_open_file): use open, not fopen.
	#include fcntl.h
	* ports.h (struct scm_port_table): change stream from SCM to void *.
	* ports.c (scm_add_to_port_table): check for memory allocation error.
	(scm_prinport): remove MSDOS hair.
	(scm_void_port): set stream to 0 instead of SCM_BOOL_F.
	(scm_close_port): don't throw errors: do it in fports.c.