system: Add a 'system?' field to user accounts.

* gnu/system/shadow.scm (<user-account>)[system?]: New field.
* gnu/system.scm (user-account->gexp): Add it.
* guix/build/activation.scm (add-user): Add #:system? parameter and
  honor it.
  (activate-users+groups): Handle the 'system?' part of user tuples.
  Pass it to 'add-user'.  Don't create PROFILE-DIR when SYSTEM? is
  true.
* gnu/services/dbus.scm (dbus-service): Add 'system?' field for
  "messagebus" account.
* gnu/services/base.scm (guix-build-accounts): Likewise.
* gnu/services/avahi.scm (avahi-service): Likewise.

system: Install /var/guix/profiles/system-1-link on new systems.

* guix/build/install.scm (directives): Add /var/guix/profiles/system.
  (populate-root-file-system): Add 'system' parameter.  Create
  /var/guix/profiles/system-1-link.
* guix/scripts/system.scm (install): Pass OS-DIR to
  'populate-root-file-system'.
* guix/build/vm.scm (initialize-root-partition): Add #:system-directory
  parameter, and pass it to 'populate-root-file-system'.
  (initialize-hard-disk): Add #:system-directory parameter, and pass it
  to 'initialize-root-partition'.
* gnu/system/vm.scm (qemu-image): Add #:os-derivation parameter and pass
  it to 'initialize-hard-disk'.
  (system-disk-image, system-qemu-image,
  system-qemu-image/shared-store): Pass #:os-derivation to 'qemu-image.

system: Support the addition of old entries in the GRUB menu.

* gnu/system.scm (operating-system-grub.cfg): Add 'old-entries'
  parameter.  Pass it to 'grub-configuration-file'.
* gnu/system/grub.scm (grub-configuration-file): Add #:old-entries
  parameter.  Honor it.

install: Use udev.

* gnu/system/install.scm (installation-services): Call 'udev-service'.

system: Use the default 'groups' field.

* gnu/system/install.scm (installation-os): Remove 'groups' field.
* build-aux/hydra/demo-os.scm: Likewise.

system: Augment the default set of groups.

* gnu/system/shadow.scm (%base-groups): New variable.
* gnu/system.scm (<operating-system>)[groups]: Use it as the default.

system: Remove useless 'members' field of 'user-group'.

* gnu/system/shadow.scm (<user-group>)[members]: Remove field.
* gnu/system/install.scm (installation-os)[users]: Remove 'members'
  fields.  Use 'supplementary-groups' for 'guest'.
* build-aux/hydra/demo-os.scm (users): Likewise.
* gnu/services/base.scm (guix-service): Remove 'members' field.

Merge branch 'master' into core-updates

install: Add missing argv[0] in Info invocation.

* gnu/system/install.scm (log-to-info): Add "info" as second argument to
  'execl'.

vm: Add #:name parameter for 'system-disk-image'.

* gnu/system/vm.scm (system-disk-image): Add #:name parameter; pass it
  to 'qemu-image'.

install: Register the hydra.gnu.org key on the installation image.

* gnu/services/base.scm (hydra-key-authorization): New procedure.
  (guix-service): Add #:authorize-hydra-key? parameter; honor it using
  'hydra-key-authorization'.
* gnu/system/install.scm (installation-services): Pass
  #:authorize-hydra-key? #t.

system: Define '%base-packages' and use it.

* gnu/system.scm (<operating-system>)[packages]: Change default value to
  %BASE-PACKAGES.
  (%base-packages): New variable.
* gnu/system/install.scm (installation-os): Use it when defining the
  'packages' field.
* doc/guix.texi (Using the Configuration System): Use %BASE-PACKAGES in
  example.  Remove now unneeded module imports.  Explain this.

install: Add more useful packages.

* gnu/system/install.scm (installation-os)[packages]: Add isc-dhcp,
  net-tools, ddrescue, kbd, and texinfo-4.

gnu: Merge Parted, fdisk, and ddrescue in (gnu packages disk).

* gnu/packages/parted.scm: Rename to...
* gnu/packages/disk.scm: ... this.  New file.  Merge with...
* gnu/packages/fdisk.scm: ... this; remove file;
* gnu/packages/ddrescue.scm: ... and this; remove file.
* gnu/system/install.scm, gnu/system/vm.scm: Adjust accordingly.
* gnu-system.am (GNU_SYSTEM_MODULES): Remove
  gnu/packages/{parted,fdisk,ddrescue}.scm and add
  gnu/packages/disk.scm.

system: File system sources can be marked as labels or devices.

* gnu/system/file-systems.scm (<file-system>)[title]: New field.
* gnu/services/base.scm (file-system-service): Add #:title parameter.
  In 'start' gexp, use 'canonicalize-device-spec' and honor TITLE.
* gnu/system.scm (other-file-system-services,
  operating-system-root-file-system, operating-system-initrd-file):
  Adjust accordingly.
* gnu/system/linux-initrd.scm (file-system->spec): Likewise.
* gnu/system/vm.scm (system-disk-image): Add 'title' field for the root
  file system.
* guix/build/linux-initrd.scm (mount-file-system): Expect the second
  element of SPEC to be the title.
  (boot-system)[root-mount-point?, root-fs-type]: Likewise.
* gnu/services/dmd.scm (dmd-configuration-file): Select
  'canonicalize-device-spec'.

Add (gnu system install).

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

vm: disk-image: Specify the root file system using a label.

* gnu/system/vm.scm (system-disk-image)[root-label]: New variable.
  Use it for the root file system, and pass it as #:file-system-label to
  'qemu-image'.

vm: Allow a volume name to be specified for the root partition.

* guix/build/vm.scm (format-partition): Add #:label parameter, and honor
  it.
  (initialize-hard-disk): Add #:file-system-label parameter, and pass it
  to 'format-partition'.
* gnu/system/vm.scm (qemu-image): Add #:file-system-label parameter and
  pass it to 'initialize-hard-disk'.

Merge branch 'master' into core-updates

vm: Disable QEMU networking in the disk image initrd.

* gnu/system/linux-initrd.scm (qemu-initrd): Add #:qemu-networking?
  parameter and honor it.
* gnu/system/vm.scm (system-disk-image): Pass #:qemu-networking #f.