Detect libz and, if present, define HAS_LIBZ and add -lz to Makefile's
LIBS variable.

Add entry on optional zlib package requirement.

Detect both uncompressed and gzipped kernel modules.

Some Linux distros (like ArchLinux) use gzipped kernel modules with
filenames like ext2.ko.gz.  This change modifies the filename pattern
from (e.g.) "ext2.ko" to "ext2.ko*".

When available, use libz to read the module.

The init_module system call requires uncompressed kernel module bytes.
On some systems (e.g. ArchLinux) the modules are gzipped on disk.
Libz is used to read and uncompress gzipped disk files (*.ko.gz) or
transparently read uncompressed modules (*.ko).

Add module loading functionality into init.c, thus making
insmod.static unnecessary.

This is not packaged on Debian/Ubuntu, but we require it.  Fail
with a useful error message if it is not available.

This complete rewrite of the building tools turns febootstrap
into a general purpose, cross-distro, supermin appliance only
build tool.

There is now only one program 'febootstrap' which is used to
build a supermin appliance from a list of packages.

Normal appliances are not supported.

The tools are incompatible with febootstrap 2.x (use the
febootstrap-2.x branch from git to get the old package).

This commit also pulls in the automake C dependencies and gnulib.

febootstrap-supermin-helper is modified so that it has the
--kmods option (to read the whitelist, from the old shell script),
and so that it can read supermin appliances composed of multiple
parts from out of a directory.

Also: Updates to documentation.