This was crucial for e2k rescue image supporting
multiple CPU versions but can be useful elsewhere.

No need to deduce kernel version again,
just save it in a temporary file.

The main reason to change what worked is
that e2k kernel-image package has Linux bits
named as image-$kver and not vmlinuz-$kver;
the guessing logic taking all of this into
account resulted in non-aesthetic patch.

NB: there's a duplicating script within
    kernel feature; it wasn't easy to avoid
    this and it might differ when handling
    multiple kernels, I didn't think much
    about this now as vm images tend to ship
    with the sole one.

It's probably a good year to get rid of this reference practice
resulting in a known sort of misdocumentation over time :-/

This change is done to reduce ambiguity in some cases;
the previous intention has been to ease navigation when
staying in a particular directory, now it's been changed
in favour of convenient toplevel `git grep' in fact.

Both variants have their pros and cons, I just find myself
leaning to this one by now hence the commit.  Feel free to
provide constructive criticism :)

Some path-related bitrot has also been fixed while at that.

Yes, mkimage-profiles is now able to build VM disk images.
So far the support is pretty basic:

- a single hard drive image with a single partition/FS
- only stock root password is configurable
- LILO is hardwired as a bootloader

The resulting images tend to boot under qemu/kvm though.

Please see doc/vm.txt for the warning regarding additional
privileges and setup required.  This was started back in
February but I still hoped to avoid sudo/privileged helper
(and libguestfs is almost as undistributable as can be)...

Thanks:

- http://blog.quinthar.com/2008/07/building-1gb-bootable-qemu-image-using.html
- Alexey Morarash who reworked that as https://github.com/tuxofil/linsygen
- led@, legion@, vitty@, aen@ for providing advice and inspiration