Bug#916716: live-wrapper: Replace vmdebootstrap usage with alternative

[Alf Gaida <agaida@siduction.org>]

Hi Scott,

the "something else" part is the funny one :P. Yes, there are some very
generic alternatives to vmdebootstrap - you might guess them:
* debootstrap
* cdebootstrap

Thats all, downside is that one has to write all the things that
vmdebootstrap provides new - so there are only two chances:
* write all the glue code and the missing parts from the scratch (should
be no problem, it has be done before)
* wait for the successor of vmdebootstrap and write another wrapper
based on a wrapper for debootstrap.

My 2 cent

Alf

PS: If that sounds to negative - sorry, was not my intention. But there
are only two options - make a debian iso wrapper around (c)debootstrap -
it's done in the former sidux/aptosid's f.u.l.l.s.t.o.r.y and is called
pyfll (https://github.com/fullstory/pyfll and
https://github.com/fullstory/python-fll and some other glue packages
(fll-liveinitscripts  and -initramfs) - downside here: It's python2 and
would need to be ported and cleaned up for long time usage in debian.

PPS: The code could be stripped down to the really needed functions for
debian - and should provide the needed interfaces for derivatives.