Bug#774339: Dependencies

[jnqnfe <jnqnfe@gmail.com>]

Package: live-build
Version: 4.0.4-1

In addition to bug #774326 (wget dependency) and the existing
dependencies of debootstrap and cpio, I believe that several other
packages should also be listed as live-build dependencies.

This includes the following, for which binaries are used (at host level):

Depends:
 - util-linux (getopt, mkswap)
 - mount
 - coreutils (cp, mv, rm, touch, mkdir, wc, stat, basename, chroot,
echo, printf, uname, date, expr, sort, uniq, dirname, head, du, dd,
rmdir, chmod, ls, tr, cat, cut, pwd, ln; and also sha256sums which will
be needed by the #718225 solution)
 - findutils (xargs, find)
 - grep
 - dpkg (dpkg, dpkg-query)
 - sed
 - gawk
 - gzip (gzip, gunzip, these are used in various places with no choice
for other compression tools, as well as in places where there is choice)
 - tar
 - diffutils (diff)
 - debianutils (which)
 - apt-utils (apt-ftparchive used by binary_package-lists script on line
159 and not within chroot, if there are any package lists, which there
always are, since config makes one)
 - dctrl-tools (grep-aptavail used in share/bin/Packages script)
 
Recommends:
 - sparc-utils (elftoaout and piggyback/piggyback64 used for sparc
netboot images)
 - gpgv (used for progress-linux in bootstrap_archive-keys, though will
need to be elevated to depends section for the #718225 solution; could
have gpgv2 as an alternative if the #773775 enhancements are accepted,
which is also supported by my #718225 solution).

Suggests:
 - udev (udevadm binary used if available by functions/losetup.sh)
 - man-db (man command, used by functions/man.sh if available)
 - git (used if pulling a config via git)

cpio should actually perhaps be elevated from its existing status under
recommends to depends, since it is required by the
installer_debian-installer script for all non-netboot builds in that
script, and thus in my mind falls under 'required to provide a
significant amount of functionality'.

There's also an issue with certain configurable items (e.g. where the
user has a choice of compression utility) where there is no check within
Check_defaults() that the binary exists, and another issue that for at
least one instance of a utility run under chroot no Check_package()
based check is performed; but both of these can be addressed separately.
In fact I have now reported them separately.