* util/update-grub.in: Fix a few assumptions about the devices holding
/, /boot and /boot/grub being the same.
* util/grub.d/00_header.in: Likewise.
* util/grub.d/10_hurd.in: Likewise.
* util/grub.d/10_linux.in: Likewise.
* util/grub.d/10_linux.in: Implement Linux image sorting with arbitrary
patterns. Use that to define the `.old' suffix as older than `'.
* util/grub.d/00_header.in: Set default gfxmode to `800x600x16'.
* util/update-grub.in: Add a reference to ${sysconfdir}/default/grub in
the grub.cfg header message.