Pull SMALLPROG stuff to disable unnecessary partitioning methods etc.

Add (experimental) entropy input support:
Early during new installs or after upgrades we check if entropy is
available. If not (no hardware random number generator available)
we inform the user and ask them to fix it.

Rework internal data structures and "interfaces to user interface" functions
to get rid of all disklabel assumptions.

Previously (even for GPT partitioning) struct disklabel was used, which
obviously breaks large disk setups. Also many MD parts and parts of the
user interface assumed (a) a struct disklabel is used internally to
store partitioning information and (b) partitions are named 'a' ... $MAXPART.

Get rid of this and replace it with a quite abstract interface that should
be able to deal with all variants in partition storage:

- partitions are stored in a (partly abstract) struct disk_partitions
and most parts of it are only accessed via accessor functions provided
by a "partitioning scheme".

- implement partitioning schemes for MBR, disklabel and GPT (with likely
RDB [amiga] and Apple Partition Map [mac*] to follow soon)

- partitioning schemes may be cascaded, e.g. on x86 when using MBR as
"outer partitions", we have disklabel as "inner partitions".

- all user interface goes via accessor functions in the partitioning scheme,
some of which return pointers to special user interface descriptors
(e.g. to allow editing partition flags, which are scheme specific)

Overall the user interface changes (in this initial step) are minimal but
noticable. A new Anita is needed for automatic test setups - many thanks
to Andreas Gustafsson for lots of early testing and a new Anita version,
and to Manuel Bouyer for cooperation and tests of the Anita release.

This work was sponsored by The NetBSD Foundation, Inc.

Enable NOPARTMAN for install media.

branches: 1.2.14; 1.2.16;
Drop ancient AOUT2ELF option. Saves ~280 bytes.

branches: 1.1.2; 1.1.6;
Move sysinst sources to usr.sbin.

This commit only physically moves the sources - there are no other
changes, to maximize the probability that this will be treated as a
rename if we ever do manage to migrate away from CVS.

Moving sysinst has been discussed on and off for years and has two
goals: making it easier to work on sysinst, and also making sysinst
available on running systems for use installing chroots and VM images
and other such things. None of the latter is possible yet, but as they
say, one thing at a time.

Doing this now was approved in an impromptu fashion by mrg, riz,
riastradh, me, and groo.