* fports.c (scm_fdes_to_port): always set rw_random if the fdes is

	* fports.c (scm_fdes_to_port): always set rw_random if the fdes is
	random access.  rw_active needs to be maintained even for single
	directional ports, otherwise scm_seek and probably other things are
	broken.  (thanks to Roland Orre).

	* strports.c (scm_mkstrport): set rw_random to 1 unconditionally.

	* ports.c (scm_add_to_port_table): initialise rw_random to 0.

	* ports.h (scm_port): change the comments on rw_random and rw_active.