Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

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

Import the skein hashing algorithm, based on the threefish block cipher

Connect it to userland (libmd, libcrypt, sbin/md5) and kernel (crypto.ko)

Support for skein as a ZFS checksum algorithm was introduced in r289422
but is disconnected because FreeBSD lacked a Skein implementation.

A further commit will enable it in ZFS.

Reviewed by: cem
Sponsored by: ScaleEngine Inc.
Differential Revision: https://reviews.freebsd.org/D6166

Dereference nonexistent md2(3) manual.

MFC after: 3 days
Sponsored by: The FreeBSD Foundation

Expand *n't contractions.

Sort sections.

Eliminate double whitespace.

Assorted mdoc(7) fixes:

- fix hard sentence breaks
- sprinkle a few .Vt's where neccessary
- remove incorrect use of `\-'
- proper quoting using .Dq, instead of manual ``...''

Approved by: des@ (mentor)
Reviewed by: ru@

The .Fn function

Modernize my email address.

mdoc(7) police: Use the new .In macro for #include statements.

Remove whitespace at EOL.

mdoc(7) police: removed HISTORY info from the .Os call.

mdoc(7) police: use proper markup for function arguments.

Add a new entrypoint to the hashes in libmd:
char *
FooFileChunk(const char *filename, char *buf, off_t offset, off_t length)
Which only hashes part of a file.
Implement FooFile() in terms of this function.

Submitted by: roam

mdoc(7) police: removed history info from the .Os FreeBSD call.

Introduce .Lb macro to libmd manpages

$Id$ -> $FreeBSD$

Add Eric Young's RIPEMD160 implementation as well, in case SHA-1
should prove weak. Also fix a few problems with the SHA-1 build.