* guix/scripts/offload.scm (lock-machine): Add 'hint' parameter.
  (unlock-machine): Remove 'machine' parameter.
  (with-machine-lock): Add 'hint' parameter, and pass it down.
  (process-request): Adjust uses of 'with-machine-lock' to pass the
  'bandwidth hint.

* guix/utils.scm (F_SETLK): New variable.
  (fcntl-flock): Add 'wait?' keyword parameter; honor it.
* tests/utils.scm ("fcntl-flock non-blocking"): New test.

* doc/guix.texi (Invoking guix package): Explain where packages are
  searched for and link to "Package Modules".
  (Defining Packages) <example>: Use 'define-module' clause instead of
  'use-modules'.  Explain why and link to "Package Modules".
  (Invoking guix build): Explain where packages aer searched for and
  link to "Package Modules".
  (Package Modules): Explain that (gnu packages ...) is scanned.

* gnu/packages/pretty-print.scm: New file
* gnu/packages/patches/source-highlight-regexrange-test.patch: New file
* gnu-system.am (dist_patch_DATA): Add patch.
(GNU_SYSTEM_MODULES): Add pretty-print.scm

This fixes a regression introduced in
99fbddf9 ("store: Change 'export-paths'
to always export in topological order.")

* guix/store.scm (export-paths): Define 'ordered' variable.  Iterate
  over it.
* tests/store.scm ("export/import paths, ensure topological order"): Add
  'file0'.  Adjust accordingly.

* gnu/packages/mpd.scm (ncmpc): New variable.

* guix/utils.scm (%libc-errno-pointer, errno): New procedures.
  (fcntl-flock): Use it as the exception's argument.

* guix/scripts/offload.scm (machine-lock-file, lock-machine,
  unlock-machine): New procedures.
  (with-machine-lock): New macro.
  (process-request): Wrap 'send-files' and 'retrieve-files' calls in
  'with-machine-lock'.

* tests/utils.scm (temp-file): New variable.
  ("fcntl-flock"): Rewrite to actually test whether the child process
  waits for the lock to be released.  The previous test was wrong
  because (1) it expected F_SETLK semantics, not F_SETLKW, and (2) it
  got EBADF because of a mismatch between the open mode and the lock
  style.

* guix/download.scm (url-fetch): Pass #:local-build? #t to
  'build-expression->derivation'.
* guix/git-download.scm (git-fetch): Likewise.

* gnu/packages/messaging.scm (bitlbee): New variable.
* gnu/packages/patches/bitlbee-fix-tests.patch: New file.
* gnu/packages/patches/bitlbee-memset-fix.patch: New file.
* gnu-system.am (dist_patch_DATA): Add patches.

* gnu/packages/messaging.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

* gnu/packages/gnupg.scm (gnupg-1): New variable.

* gnu/packages/lynx.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

* gnu/packages/gnutls.scm (gnutls): Upgrade to 3.2.12.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

* gnu/packages/python.scm (python2-element-tree, python2-pybugz): New
  variables.

* doc/guix.texi (Invoking guix package): Remove documentation for
  --dry-run, --fallback, --no-substitutes, and --max-silent-time.  Add a
  cross-ref to "Invoking guix build".
  (Invoking guix archive): Add "common build options" as the cross-ref
  topic for "Invoking guix build".
  (Invoking guix build): Move common build options separately.  Add a
  paragraph to explain.

* gnu/packages/version-control.scm (subversion): Update to 1.7.14.

* gnu/packages/version-control.scm (subversion): Add input neon-0.29.6 to
    enable http and https checkouts.

* gnu/packages/version-control.scm (neon-0.29.6): New variable.

* gnu/packages/version-control.scm (neon): New variable.

* gnu/packages/hurd.scm (hurd-headers): New variable.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

* guix/scripts/build.scm (%standard-build-options): Change option
  handlers to support multiple seeds.
* guix/scripts/package.scm (show-help): Remove --dry-run, --fallback,
  --no-substitutes, and --max-silent-time.
  (%options): Likewise, and add %STANDARD-BUILD-OPTIONS.
  (%default-options): Add 'verbosity'.
  (guix-package): Call 'set-build-options-from-command-line' instead of
  'set-build-options'.

* gnu/packages/ssh.scm (guile-ssh): Upgrade to 0.5.0.
  [arguments]: Adjust 'autoreconf' phase.  Add #:parallel-tests? #f and
  #:tests? #f.
  [native-inputs]: Add TEXINFO.

* guix/http-client.scm (&http-get-error): New condition type.
  (http-fetch): Raise it instead of using 'error'.
* guix/scripts/substitute-binary.scm (fetch) <http>: Wrap body into
  'guard' form; gracefully handle 'http-get-error?' conditions.

* guix/scripts/offload.scm (open-ssh-gateway): Comment out.
  (process-request): Remove call to 'open-ssh-gateway' and to 'kill'.

* guix/scripts/offload.scm (remote-pipe): Pass -i when invoking
  %LSHG-COMMAND.

* guix/scripts/offload.scm (machine-load, machine-less-loaded?,
  machine-less-loaded-or-faster?): New procedures.
  (choose-build-machine): Use 'machine-less-loaded-or-faster?' when
  sorting.  Return the head of MACHINES unless it's loaded is >= 2.

* guix/scripts/archive.scm (show-help): Add '--authorize'.

* gnu/packages/bdw-gc.scm (libgc)[source, home-page, license]: Update
  URL.
  (libatomic-ops)[source, home-page]: Likewise.
  (libgc-7.4)[source]: Likewise.

* guix/gnu-maintenance.scm (latest-release)[patch-directory-name?]: New
  procedure.
  <subdirs>: Use it to filter out Bash-like patch directories.

* build-aux/hydra/gnu-system.scm (package->alist): Add 'timeout' item.

* gnu/packages/libwebsockets.scm: Remove.  Move libwebsockets package
  definition to...
* gnu/packages/web.scm (libwebsockets): ... here.
* gnu-system.am (GNU_SYSTEM_MODULES): Remove libwebsockets.scm.

* guix/store.scm (set-build-options): Use 'when' instead of 'if'.

* gnu/packages/mpd.scm (mpd): New variable.

* gnu/packages/mpd.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

* gnu/packages/zile.scm (zile): Upgrade to 2.4.10

* gnu/packages/parallel.scm (parallel): Upgrade to 20140222

* gnu/packages/video.scm (ffmpeg): Upgrade to 2.1.4.

* gnu/packages/gnunet.scm (libmicrohttpd): Update to 0.9.34.