Nowadays, lipck generates its own image with up to date bootloaders,
etc. Furthermore, a brand new sparse multiboot image may be created
using the multiboot target of lipck. So the blob is no longer
useful in any way.

This target may be used to create an empty multiboot image (only the
bootloader is installed). This is intended to be used manually to
either debug the crucial part of the bootloader installation, or just
because a multiboot image comes in handy for another purpose.

Previously, the efi bootloaders were installed in several places.
The main reason was to be compatible with the lipstick grub.cfg
and the ubuntu secure boot grub. This commit unifies the location.
Hence, old lipstick grub.cfg`s are no longer compatible; we need at
least commit
	786f37351916396cb59d21e573d6be372089e516
of the lipstick repository to have a (fully) working grub.cfg.

(i.e. at the same time the content is created)

because this will fail (we copy to a fat fs)...

with the ubuntu secure boot grub located in /boot/grub.

image_skel_file will now create a partition image (with FAT fs)
while the new image_assemble target will create a proper device
image from this partition (in particular, it adds a partition table).

This allows us to mount the partition and deploy the finished
image to a custom location in the end.

Since lipck knows the release it can do it and nobody will miss
to edit the static sources.list again (in particular, this sucks
when trying out new releases)

lipck generates a prober ORDER file on the fly. Hence, the static
file is not required (and it had the disadvantage that it may not
match the initrd version)

All files placed in contrib/rootfs/sysctl.d/ will be copied to
/etc/sysctl.d in the rootfs as is.

-offline repo has been implemented
-set -e bug has been fixed