git-authenticate: Don't hard-code "origin/" for keyring reference.

* guix/git-authenticate.scm (load-keyring-from-reference): Remove
hard-coded "origin/".  Use BRANCH-ALL instead of BRANCH-REMOTE.

Add (guix git-authenticate).

* build-aux/git-authenticate.scm (commit-signing-key)
(read-authorizations, commit-authorized-keys, authenticate-commit)
(load-keyring-from-blob, load-keyring-from-reference)
(authenticate-commits, authenticated-commit-cache-file)
(previously-authenticated-commits, cache-authenticated-commit): Remove.
* build-aux/git-authenticate.scm (git-authenticate): Pass
 #:default-authorizations to 'authenticate-commits'.
* guix/git-authenticate.scm: New file, with code taken from
'build-aux/git-authenticate.scm'.  Remove references to
'%historical-authorized-signing-keys' and add #:default-authorizations
parameter instead.
* Makefile.am (MODULES): Add it.
(authenticate): Depend on guix/git-authenticate.go.

gnu: boost-signals2: Update hash.

Reported by pkill9 on #guix.

* gnu/packages/boost.scm (boost-signals2)[source]: Fix the hash.

gnu: diffoscope: Update to 146.

* gnu/packages/diffoscope.scm (diffoscope): Update to 146.

gnu: diffoscope: Remove redundant let binding.

* gnu/packages/diffoscope.scm (diffoscope): Unbind VERSION.

gnu: docker, docker-cli: Update to 19.03.9.

* gnu/packages/docker.scm (%docker-version): Update to 19.03.9.
(docker, docker-cli): Update hashes.

gnu: websocketpp: Update to 0.8.2.

* gnu/packages/web.scm (websocketpp): Update to 0.8.2.
[source]: Replace patch.
* gnu/packages/patches/websocketpp-fix-for-boost-1.70.patch: Delete file.
* gnu/packages/patches/websocketpp-fix-for-cmake-3.15.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

gnu: strace: Update to 5.7.

* gnu/packages/linux.scm (strace): Update to 5.7.
[arguments]: Disable three failing tests.

gnu: singular: Update to 4.1.3p1.

* gnu/packages/algebra.scm (singular): Update to 4.1.3p1.

gnu: iproute2: Update to 5.7.0.

* gnu/packages/linux.scm (iproute): Update to 5.7.0.

gnu: man-db: Update to 2.9.2.

* gnu/packages/man.scm (man-db): Update to 2.9.2.

gnu: fetchmail: Update to 6.4.6.

* gnu/packages/mail.scm (fetchmail): Update to 6.4.6.

gnu: synapse: Update to 1.14.0.

* gnu/packages/matrix.scm (synapse): Update to 1.14.0.

gnu: guix: Update to ea924134f8.

Update Guix to include ea924134f819eef072ba7df9080d39de97fd73e6, that fixes a
test failure that can occur when running from a file-system without user_xattr
support.

* gnu/packages/package-management.scm (guix): Update to 1.1.0-6.ea92413.

tests: syscall: Support file-systems without extended attributes.

* tests/syscalls.scm (setxattr): Catch ENOTSUP that can be raised if the
file-system does not support extended user attributes.

gnu: Add cl-1am.

* gnu/packages/lisp-xyz.scm (sbcl-1am, cl-1am, ecl-1am): New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu: Add cl-sxql.

* gnu/packages/lisp-xyz.scm (sbcl-sxql, cl-sxql, ecl-sxql): New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu: Add cl-exponential-backoff.

* gnu/packages/lisp-xyz.scm (sbcl-exponential-backoff, cl-exponential-backoff,
  ecl-exponential-backoff): New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu: Add cl-rove.

* gnu/packages/lisp-xyz.scm (sbcl-rove, cl-rove, ecl-rove): New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>

gnu: Add cl-dissect.

* gnu/packages/lisp-xyz.scm (sbcl-dissect, cl-dissect, ecl-dissect):
  New variables.

Signed-off-by: Guillaume Le Vaillant <glv@posteo.net>