Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Revert 239931 and 239932 until I figure out why it breaks on stable branches
but not on -HEAD.

Noticed by: tinderbox
Pointy hat to: delphij

MFC r238964:

Teach md5(1) about sha512.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Switch the default WARNS level for sbin/ to 6.

Submitted by: Ulrich Spörlein

In light of the recent 2^69 operation collision-finding attack on SHA1,
add support for SHA256.

Tested on: i386, sparc64
Tested using: NIST test vectors, built-in tests
X-MFC-after: 5.4-RELEASE

Add sha1 and rmd160 checksum tools.

Since the algorithms are already supported in libmd,
the size increase is small when a dynamic root is used.

Approved by: joerg, ru
MFC after: 2 weeks

Fixed style of DPADD and LDADD assignments as per style.Makefile(5).

Default to WARNS=2.
Binary builds that cannot handle this must explicitly set WARNS=0.

Reviewed by: mike

WARNS= -> WARNS?=

Submitted by: Mike Barcroft <mike@q9media.com>

Fix argument processing.
Make this compile with WARNS=2.

PR: bin/27524
MFC after: 3 days

- Backout botched attempt to introduce MANSECT feature.
- MAN[1-9] -> MAN.

Set the default manual section for sbin/ to 8.

/usr/lib/libmd.a -> ${LIBMD}

This commit was generated by cvs2svn to compensate for changes in r3995,
which included commits to RCS files with non-trunk default branches.

Incorproate version of md5 placed into public domain by RSA.