Merge branch 'master' into core-updates

install: Use a low-memory nscd caching policy.

* gnu/system/install.scm (%nscd-minimal-caches): New variable.
  (installation-services): Use as 'nscd-service' argument.

Merge branch 'master' into 'core-updates'.

system: grub: Make sure the font and background image are always found.

* gnu/system/grub.scm (eye-candy): Add 'search --file --set'.

system: Adjust 'grub.cfg' to work on systems with a separate /boot.

Fixes <http://bugs.gnu.org/19220>.
Reported by Nikita Karetnikov <nikita@karetnikov.org>.

* gnu/system/grub.scm (grub-configuration-file)[entry->gexp]: Add
  'search --file --set'.
  (grub-configuration-file)[builder]: Remove 'search.file'.

vm: Use QEMU's standard VGA emulation by default.

* gnu/system/vm.scm (common-qemu-options): Add "-vga std".

system: Add skeleton '.zlogin'.

* gnu/system/shadow.scm (default-skeletons): Add .zlogin.

system: Cleanup bash startup files.

* gnu/system.scm (etc-directory) (bashrc): Rename to 'profile'.
* gnu/system/shadow.scm (default-skeletons): Rename '.bashrc' to
  '.bash_profile'. Don't source /etc/profile.

linux-initrd: Add the 'virtio_console' module for QEMU guests.

* gnu/system/linux-initrd.scm (base-initrd)[virtio-modules]: Add
  "virtio_console".

Revert "system: Add a 'needed-for-boot?' field to 'mapped-device'."

This reverts commit 3b09332adf7ce8e976a4d117a62c586a53af04aa, which
turned out to be a bad idea because we need to have dependency
information between the device-mapping service and the file-system
service that uses it.

system: locale: Fix typo in docstring.

* gnu/system/locale.scm (localedef-command): Fix typo.

system: Add a 'needed-for-boot?' field to 'mapped-device'.

* gnu/system/file-systems.scm (<mapped-device>)[needed-for-boot?]: New
  field.
* gnu/system.scm (operating-system-user-mapped-devices,
  operating-system-boot-mapped-devices): Use it instead of trying to
  guess.  Guessing doesn't work when one refers to a partition using its
  label, for instance.
* doc/guix.texi (Mapped Devices): Document 'needed-for-boot?'.

system: Change "en_US.UTF-8" to "en_US.utf8".

* build-aux/hydra/demo-os.scm (locale): Change to "en_US.utf8".
* gnu/system/install.scm (installation-os)[locale]: Ditto.

linux-initrd: Remove the ".ko" suffix from module names in 'base-initrd'.

* gnu/system/linux-initrd.scm (base-initrd): Remove the .ko suffix from
  module names.

linux-initrd: Remove now redundant module names.

* gnu/system/linux-initrd.scm (base-initrd)[virtio-modules]: Remove
  "virtio.ko" and "virtio_ring.ko".
  [virtio-9p-modules]: Remove "fscache.ko" and "9pnet.ko".
  [linux-modules]: Remove "libahci.ko".

linux-boot: Load modules and their dependencies, à la 'modprobe'.

* gnu/build/linux-boot.scm: Use (gnu build linux-modules).
  (load-linux-module*): Remove.
  (boot-system): Add #:linux-module-directory parameter.
  [lookup-module]: New procedure.
  Call 'current-module-debugging-port'.  Pass #:lookup-module to
  'load-linux-module*'.  Map LOOKUP-MODULE on LINUX-MODULES.
* gnu/system/linux-initrd.scm (base-initrd): Adjust 'boot-system' call
  accordingly.  Adjust #:modules argument as well.
* gnu/system.scm (operating-system-activation-script)[%modules]: Likewise.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Likewise.

linux-initrd: Copy modules and their dependencies to the initrd.

* gnu/system/linux-initrd.scm (flat-linux-module-directory)[build-exp]:
  Add 'lookup' procedure.  Use 'recursive-module-dependencies' to
  compute the list of modules to copy.
  Adjust #:modules parameter.

system: Build system-wide locale definitions.

* gnu/system/locale.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.
* gnu/system.scm (<operating-system>)[locale]: Change the default to
  "en_US.utf8".
  (operating-system-locale-directory): New procecure.
  (operating-system-derivation): Use it.
* doc/guix.texi (Using the Configuration System): Change example locale
  to "fr_FR.utf8".
  (operating-system Reference): Add xref to "Locales".  Document
  'locale-definitions'.
  (Locales): New section.
* po/guix/POTFILES.in: Add gnu/system.scm.

file-systems: 'file-system-needed-for-boot?' always returns #t for "/".

Reported by Nikita Karetnikov.

* gnu/system/file-systems.scm (<file-system>): Rename 'needed-for-boot?'
  accessor to '%file-system-needed-for-boot?'.
  (file-system-needed-for-boot?): New inlinable procedure.
* gnu/system.scm (other-file-system-services)[file-systems]: Rely on
  'file-system-needed-for-boot?' to handle the "/" case.
  (operating-system-initrd-file)[boot-file-systems]: Likewise.

install: Add wpa-supplicant to the image.

Reported by Amirouche Boubekki <amirouche.boubekki@gmail.com>.

* gnu/system/install.scm (installation-os)[packages]: Add
  WPA-SUPPLICANT.