* grub-core/io/gzio.c (grub_gzio_open): Removed "transparent" parameter.

	* grub-core/io/gzio.c (grub_gzio_open): Removed "transparent" parameter.
	Made static.
	(grub_gzfile_open): Removed. All users updated.
	(GRUB_MOD_INIT): New function.
	(GRUB_MOD_FINI): Likewise.
	* grub-core/kern/file.c (grub_file_filters_all): New variable.
	(grub_file_filters_enabled): Likewise.
	(grub_file_open): Handle filters.
	* grub-core/loader/i386/bsd.c (GRUB_MOD_INIT): Load gzio.
	* grub-core/normal/main.c (GRUB_MOD_INIT): Likewise.
	* include/grub/file.h (grub_file_filter_id_t): New type.
	(grub_file_filter_t): Likewise.
	(grub_file_filters_all): New extern variable.
	(grub_file_filters_enabled): Likewise.
	(grub_file_filter_register): New inline function.
	(grub_file_filter_unregister): Likewise.
	(grub_file_filter_disable): Likewise.
	(grub_file_filter_disable_compression): Likewise.
	* include/grub/gzio.h: Removed.