set debconf title

This fixes a user report where man-db title where being used during
grub installation since no other module has change it until
grub-installer has been started.
Use '+squeeze' as per developper reference
releasing version 1.60+squeeze1
releasing version 1.60+squeeze1
releasing version 1.60+squeeze2
Restore the ability to choose to install GRUB Legacy by preseeding (grub-installer/grub2_instead_of_grub_legacy=false), removed in 1.60 as a side-effect of removing a warning message.  This is still useful e.g. when installing inside Xen.
releasing version 1.60+squeeze3
Make sure that 'grub-probe -t device XXX' only takes the first entry
if there's multiple (as if a mirror etc).
if $ROOT/boot/zfs doens't exist (before we try to copy the zpool.cache
file), then create it.
Copy the whole /boot/zfs directory, not just the zpool.cache file.
+ That way, if there's a crypto key in there, it gets copied to.