doc: Mention 'tzselect'.

* doc/guix.texi (operating-system Reference): Mention 'tzselect' and
invalid timezone strings.

guix system: 'reconfigure' loads and starts new services.

Partly fixes <http://bugs.gnu.org/22039>.

* gnu/services/herd.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu/services/shepherd.scm (shepherd-service-canonical-name): New
procedure.
(shepherd-service-file): Export.
* guix/scripts/system.scm (upgrade-shepherd-services): New procedure.
(switch-to-system): Use it.
* guix/ui.scm (info): New procedure.
* doc/guix.texi (Invoking guix system): Mention system services.

guix build: Add '--with-input'.

* guix/scripts/build.scm (transform-package-inputs): New procedure.
(%transformations): Add it.
(%transformation-options, show-transformation-options-help): Add
--with-input.
* tests/scripts-build.scm ("options->transformation, with-input"):
("options->transformation, with-input, no matches"): New tests.
* tests/guix-build.sh: Add tests.
* doc/guix.texi (Package Transformation Options): Document it.

guix package: Support package transformation options.

* guix/scripts/package.scm (show-help): Call
'show-transformation-options-help'.
(%options): Append %TRANSFORMATION-OPTIONS.
(process-actions)[transform, transform-entry]: New procedures.
* doc/guix.texi (Invoking guix package): Mention package
transformations.
(Package Transformation Options): Mention 'guix package'.

guix build: Separate transformation options.

* guix/scripts/build.scm (%transformation-options): New variable.
(show-transformation-options-help): New procedure.
(show-help): Remove '--with-source' documentation and add
'show-transformation-options-help' call.
(%options): Remove "with-source" and append %TRANSFORMATION-OPTIONS.
* doc/guix.texi (Package Transformation Options): New node.  Document
'--with-source', moved from...
(Additional Build Options): ... here.

doc: Add subsections to 'Invoking guix build'.

* doc/guix.texi (Invoking guix build): Add example.  Shuffle options in
the new subsections below.
(Common Build Options, Additional Build Options): New nodes.
(Invoking guix archive): Refer to "Common Build Options".
(Invoking guix environment): Likewise.
(Invoking guix system): Likewise.

fixlet

guix system: Rename 'dmd-graph' to 'shepherd-graph'.

* doc/images/dmd-graph.dot: Rename to...
* doc/images/shepherd-graph.dot: ... this.
* doc.am (DOT_FILES): Adjust accordingly.
* guix/scripts/system.scm (dmd-service-node-label)
  (dmd-service-node-type, export-dmd-graph): Rename to...
  (shepherd-service-node-label, shepherd-service-node-type)
  (export-shepherd-graph): ... this.
  (show-help, process-action, process-command): Rename 'dmd-graph' to
  'shepherd-graph'.
* emacs/guix-command.el (guix-command-additional-execute-arguments)
  (guix-command-special-executors): Likewise.
* doc/guix.texi: Likewise.
* doc/emacs.texi (Emacs Popup Interface): Likewise.

services: Rename 'dmd' services to 'shepherd'.

* gnu/services/shepherd.scm (dmd-root-service-type, %dmd-root-service)
  (dmd-service-type, <dmd-service>, dmd-service, dmd-service?)
  (make-dmd-service, dmd-service-documentation, dmd-service-provision)
  (dmd-service-requirement, dmd-service-respawn, dmd-service-start)
  (dmd-service-stop, dmd-service-auto-start?, dmd-service-modules)
  (dmd-service-imported-modules, dmd-service-file-name, dmd-service-file)
  (dmd-service-back-edges): Rename to...
  (shepherd-root-service-type, %shepherd-root-service, shepherd-service-type)
  (<shepherd-service>, shepherd-service, shepherd-service?)
  (make-shepherd-service, shepherd-service-documentation)
  (shepherd-service-provision, shepherd-service-requirement)
  (shepherd-service-respawn, shepherd-service-start)
  (shepherd-service-stop, shepherd-service-auto-start?)
  (shepherd-service-modules, shepherd-service-imported-modules)
  (shepherd-service-file-name, shepherd-service-file)
  (shepherd-service-back-edges): ...this
* gnu/services.scm: Adjust comments.
* gnu/services/avahi.scm (avahi-dmd-service): Rename to...
  (avahi-shepherd-service): ... this.
* gnu/services/base.scm (%root-file-system-dmd-service)
  (file-system->dmd-service-name, mapped-device->dmd-service-name)
  (dependency->dmd-service-name, file-system-dmd-service)
  (mingetty-dmd-service, nscd-dmd-service, guix-dmd-service)
  (guix-publish-dmd-service, udev-dmd-service, gpm-dmd-service): Rename to...
  (%root-file-system-shepherd-service)
  (file-system->shepherd-service-name, mapped-device->shepherd-service-name)
  (dependency->shepherd-service-name, file-system-shepherd-service)
  (mingetty-shepherd-service, nscd-shepherd-service, guix-shepherd-service)
  (guix-publish-shepherd-service, udev-shepherd-service)
  (gpm-shepherd-service): ... this.
* gnu/services/databases.scm (postgresql-dmd-service): Rename to...
  (postgresql-shepherd-service): ... this.
* gnu/services/desktop.scm (upower-dmd-service, elogind-dmd-service):
  Rename to...
  (upower-shepherd-service, elogind-shepherd-service): ... this.
* gnu/services/dbus.scm (dbus-dmd-service): Rename to...
  (dbus-shepherd-service): ... this.
* gnu/services/lirc.scm (lirc-dmd-service): Rename to...
  (lirc-shepherd-service): ... this.
* gnu/services/mail.scm (dovecot-dmd-service): Rename to...
  (dovecot-shepherd-service): ... this.
* gnu/services/networking.scm (ntp-dmd-service, tor-dmd-service)
  (bitlbee-dmd-service, wicd-dmd-service, network-manager-dmd-service): Rename to...
  (dbus-shepherd-service): ... this.
* gnu/services/ssh.scm (lsh-dmd-service): Rename to...
  (lsh-shepherd-service): ... this.
* gnu/services/web.scm (nginx-dmd-service): Rename to...
  (nginx-shepherd-service): ... this.
* gnu/services/xorg.scm (slim-dmd-service): Rename to...
  (slim-shepherd-service): ... this.
* gnu/system.scm (essential-services): Use '%shepherd-root-service'.
* gnu/system/install.scm (cow-store-service-type): Adjust accordingly.
* guix/scripts/system.scm (dmd-service-node-label, dmd-service-node-type)
  (export-dmd-graph): Likewise.
* tests/guix-system.sh: Likewise.
* tests/services.scm ("dmd-service-back-edges"): Rename to...
  ("shepherd-service-back-edges"): Adjust accordingly.
* doc/guix.texi: Likewise.
* doc/images/service-graph.dot: Use 'shepherd' service name.

Rename (gnu services dmd) to (gnu services shepherd).

* gnu/services/dmd.scm: Rename to...
* gnu/services/shepherd.scm: ... this.
* gnu/system.scm: Use it.
* gnu/system/install.scm: Likewise.
* gnu/services/xorg.scm: Likewise.
* gnu/services/web.scm: Likewise.
* gnu/services/ssh.scm: Likewise.
* gnu/services/networking.scm: Likewise.
* gnu/services/mail.scm: Likewise.
* gnu/services/lirc.scm: Likewise.
* gnu/services/desktop.scm: Likewise.
* gnu/services/dbus.scm: Likewise.
* gnu/services/databases.scm: Likewise.
* gnu/services/base.scm: Likewise.
* gnu/services/avahi.scm: Likewise.
* guix/scripts/system.scm: Likewise.
* tests/services.scm: Likewise.
* tests/guix-system.sh: Likewise.
* doc/guix.texi (Shepherd Services): Adjust accordingly.
* gnu-system.am (GNU_SYSTEM_MODULES): Likewise.
* po/guix/POTFILES.in: Likewise.

doc: Replace references to 'dmd' with 'shepherd'.

* doc/guix.texi: Use 'shepherd'/'herd' instead of 'dmd'/'deco'.  Fix
  info references.

doc: Describe how Emacs packages are found.

* doc/guix.texi (Application Setup)[Emacs Packages]: New subsection.

doc: Show how to boot result of 'vm-image'.

* doc/guix.texi (Running GuixSD in a VM): New node.
(Invoking guix system): Add reference to 'Running GuixSD in a VM'.

emacs: Add interface for licenses.

* emacs/guix-main.scm (%license-param-alist): New variable.
  (license->sexp, find-licenses, license-entries): New procedures.
* emacs/guix-license.el (guix-license-get-entries)
  (guix-license-get-display, guix-license-insert-packages-button)
  (guix-license-insert-comment, guix-license-list-describe)
  (guix-license-list-show-packages): New procedures.
  (guix-licenses): New command.
* doc/emacs.texi (Emacs Licenses): New node.
  (Emacs Interface): Add it.
* doc/guix.texi (Top): Add it.
* NEWS: Mention new interface.

emacs: Add 'guix-packages-by-license' command.

* emacs/guix-main.scm (packages-by-license): New procedure.
(%patterns-makers): Add 'license' search type.
* emacs/guix-messages.el (guix-message-packages-by-license): New procedure.
(guix-messages): Use it.
* emacs/guix-ui-package.el (guix-packages-by-license): New command.
* doc/emacs.texi (Emacs Commands): Document it.

emacs: Buttonize licenses in "Package Info".

* emacs/guix-ui-package.el (guix-package-license): New button type.
  (guix-package-info-format, guix-output-info-format): Use it.
* doc/emacs.texi (Emacs Info buffer): Mention it.

Merge branch 'master' into core-updates

doc: Add policy about version numbers for VCS snapshots.

* doc/guix.texi (Version Numbers): Add paragraphs about VCS snapshot
version numbers.

doc: Remove unneeded backslashes.

* doc/guix.texi (Networking Services): Remove unneeded backslashes.

doc: 'base-initrd' has #:virtio? default to #t.

This is a followup to e26d507.

* doc/guix.texi (Initial RAM Disk): #:virtio? defaults to #t.

doc: Fix typo in section on offloading.

* doc/guix.texi (Daemon Offload Setup): Fix quoting typo in command.