b2sum: a new checksum utility with md5sum like interface

Note we don't support the --algorithm option of the
b2sum command in the external BLAKE2 project, as that
was deemed too confusing for users.
"BLAKE2b" was chosen as the default algorithm to use,
which is single threaded but performs well on 64 bit.

* src/blake2: CC0 source copied from external project.
* cfg.mk[VC_LIST_ALWAYS_EXCLUDE_REGEX]: Exclude blake2/
from syntax checks, make update-copyright, etc.
* src/local.mk: Reference the sources for b2sum,
and set the compilation flags.
* doc/coreutils.texi (b2sum invocation): Reference the
md5sum invocation node, and add descriptions of -l.
* tests/misc/b2sum.sh: Add new test.
* tests/local.mk: Reference new test.
* AUTHORS: Add new binary.
* README: Likewise.
* build-aux/gen-lists-of-programs.sh: Likewise.
* man/.gitignore: Likewise.
* scripts/git-hooks/commit-msg: Likewise.
* man/b2sum.x: New man page template.
* man/local.mk: Reference new template.
* src/.gitignore: Ignore new binaries.
* src/blake2/.gitignore: Ignore new build atrifacts.
* src/md5sum.c (usage): Describe the new -l option.
* NEWS: Mention the new program.

1 files changed, 5 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 6dd6772db..e607d32a8 100644
--- a/NEWS
+++ b/NEWS
@@ -104,6 +104,11 @@ GNU coreutils NEWS                                    -*- outline -*-
   stat --format=%N for quoting file names now honors the
   same QUOTING_STYLE environment variable values as ls.
 
+** New programs
+
+  b2sum is added to support the BLAKE2 digest algorithm with
+  a similar interface to the existing md5sum and sha1sum, etc. commands.
+
 ** New Features
 
   date now accepts the --debug option, to annotate the parsed date string,