Support install on multi-device filesystems.

	Support install on multi-device filesystems.

	* include/grub/emu/getroot.h (grub_guess_root_device): Renamed to ...
	(grub_guess_root_devices): ...this. Return char **. All users updated.
	* include/grub/emu/misc.h (grub_find_root_device_from_mountinfo):
	Removed.
	* util/getroot.c (find_root_device_from_libzfs): Moved pool logic to ...
	(find_root_devices_from_poolname): ... here.
	(grub_find_root_devices_from_mountinfo): Return char **. Make static.
	Support zfs-fuse.
	(grub_guess_root_device): Rename to ...
	(grub_guess_root_devices): ... this. Return char **. All users updated.
	* util/grub-install.in: Handle multi-device filesystems.
	* util/grub-probe.c (probe). Make device_names a char **. Add delim
	argument. All users updated.
	Handle multi-device filesystems.
	Use 'delim' as separator.
	Remove device check to allow filesystems on file.
	(main): Support -0 argument. Handle multi-device.
	* util/grub-setup.c (setup): Remove root argument. Handle multi-device.
	Fix a cross-device check while on it.
	(arguments): Remove root_dev.
	(argp_parser): Remove -r.
	(main): Remove root_dev.