Merge branch 'version-0.13.0'

guix system: Don't warn about old distros for "guix system init".

* guix/scripts/system.scm (process-action): Don't call
'warn-about-old-distro' when ACTION is 'init' or 'build'.

guix system: Increase image size for 'guix system vm'.

This is a followup to 9a1bfe764859365b6726f168da95b88a2d22403b.

* guix/scripts/system.scm (system-derivation-for-action): Add 40MiB to
the default size for 'vm'.

scripts: system: Display bootloader name in "list-generations".

* guix/scripts/system.scm (display-system-generation): Display
  bootloader name.

scripts: system: Adapt "switch-generation" to new bootloader API.

* guix/scripts/system.scm (reinstall-grub): Rename to
  reinstall-bootloader. Read boot-device and boot-type from parameters file to
  be able to restore the correct bootloader on specified device.
  Factorize bootloader installation code by calling install-bootloader.
 (system-bootloader-name): New procedure.
 (switch-to-system-generation): Adapt.

scripts: system: Adapt "init" to new bootloader API.

* guix/scripts/system.scm (install): Pass installer a new
argument. Rename other arguments.
Call install-bootloader instead of install-grub*.
(perform-action): Adapt.

scripts: system: Adapt "reconfigure" to new bootloader API.

* guix/scripts/system.scm (install-grub*): Rename to install-bootloader.  Use
keys to pass arguments.  Pass a new argument, "installer-drv" which is a script
in store dealing with bootloader-specific install actions.  Also call
"install-boot-config" to install the bootloader config file.

(install-bootloader-derivation): New procedure.  It returns a derivation that
builds a file containing "install-procedure" gexp.

(perform-action): Build install-proc derivation and call install-bootloader
with the resulting file.  Stop adding GRUB to PATH as bootloaders are called in
install-proc with direct store paths.

bootloader: Add extlinux support.

* gnu/bootloader.scm: New file.
* gnu/bootloader/extlinux.scm: New file.
* gnu/bootloader/grub.scm: New file.
* gnu/local.mk: Build new files.
* gnu/system.scm: Adapt to new bootloader api.
* gnu/scripts/system.scm: Adapt to new bootloader api.
* gnu.scm: Remove (gnu system grub) and replace by (gnu bootloader) and (gnu
bootloader grub) modules.
* gnu/system/grub.scm: Moved content to gnu/bootloader/grub.scm.
* gnu/system/vm: Replace (gnu system grub) module by (gnu bootloader).
* gnu/tests.scm: Ditto.
* gnu/tests/nfs.scm: Ditto.

scripts: Warn about old distro.

Fixes <http://bugs.gnu.org/25852>.
Suggested by Mark H Weaver <mhw@netris.org>.

* guix/scripts.scm (%distro-age-warning): New variable.
(warn-about-old-distro): New procedure.
* guix/scripts/package.scm (process-actions): Call
'warn-about-old-distro'.
* guix/scripts/system.scm (process-action): Likewise.

scripts: Remove profile-grub-entries.

* guix/scripts/system.scm (profile-grub-entries): Delete variable.

system: grub: Use boot-parameters instead of menu-entry where possible.

* gnu/system/grub.scm (boot-parameters->menu-entry): New variable.
(grub-configuration-file): Use boot-parameters
instead of menu-entry where possible.
* guix/scripts/system.scm (profile-boot-parameters): Update docstring.
(reinstall-grub): Use profile-boot-parameters.
(perform-action): Use profile-boot-parameters.

scripts: Make boot-parameters label include generation number and time.

* guix/scripts/system.scm (system->boot-parameters): Make label include
generation number and time.

system: Introduce read-boot-parameters-file.

* gnu/system.scm (read-boot-parameters): Remove export.
(read-boot-parameters-file): New variable. Export it.
* guix/scripts/system.scm (profile-boot-parameters): Use
read-boot-parameters-file.
(profile-grub-entries): Use read-boot-parameters-file.
(reinstall-grub): Use read-boot-parameters-file.
(display-system-generation): Use read-boot-parameters-file.

ui: Rename '_' to 'G_'.

This avoids collisions with '_' when the latter is used as a 'match'
pattern for instance.  See
<https://lists.gnu.org/archive/html/guix-devel/2017-04/msg00464.html>.

* guix/ui.scm: Rename '_' to 'G_'.
* po/guix/Makevars (XGETTEXT_OPTIONS): Adjust accordingly.
* build-aux/compile-all.scm (warnings): Remove 'format'.
* gnu/packages.scm,
gnu/services.scm,
gnu/services/shepherd.scm,
gnu/system.scm,
gnu/system/shadow.scm,
guix/gnupg.scm,
guix/http-client.scm,
guix/import/cpan.scm,
guix/import/elpa.scm,
guix/import/pypi.scm,
guix/nar.scm,
guix/scripts.scm,
guix/scripts/archive.scm,
guix/scripts/authenticate.scm,
guix/scripts/build.scm,
guix/scripts/challenge.scm,
guix/scripts/container.scm,
guix/scripts/container/exec.scm,
guix/scripts/copy.scm,
guix/scripts/download.scm,
guix/scripts/edit.scm,
guix/scripts/environment.scm,
guix/scripts/gc.scm,
guix/scripts/graph.scm,
guix/scripts/hash.scm,
guix/scripts/import.scm,
guix/scripts/import/cpan.scm,
guix/scripts/import/cran.scm,
guix/scripts/import/crate.scm,
guix/scripts/import/elpa.scm,
guix/scripts/import/gem.scm,
guix/scripts/import/gnu.scm,
guix/scripts/import/hackage.scm,
guix/scripts/import/nix.scm,
guix/scripts/import/pypi.scm,
guix/scripts/import/stackage.scm,
guix/scripts/lint.scm,
guix/scripts/offload.scm,
guix/scripts/pack.scm,
guix/scripts/package.scm,
guix/scripts/perform-download.scm,
guix/scripts/publish.scm,
guix/scripts/pull.scm,
guix/scripts/refresh.scm,
guix/scripts/size.scm,
guix/scripts/substitute.scm,
guix/scripts/system.scm,
guix/ssh.scm,
guix/upstream.scm: Use 'G_' instead of '_'.  Most of this change was
obtained by running: "sed -i -e's/(_ "/(G_ "/g' `find -name \*.scm`".

Merge branch 'master' into staging

scripts: system: Rename --no-grub option to --no-bootloader.

* guix/scripts/system.scm (%options, show-help): Adjust accordingly.
Keep "--no-grub" for compatibility reasons, but do not mention it in the help.

Signed-off-by: Danny Milosavljevic <dannym@scratchpost.org>

services: 'service-parameters' becomes 'service-value'.

* gnu/services.scm (<service>)[parameters]: Rename to...
[value]: ... this.
Change calls to 'service-parameters' to 'service-value'.
* gnu/system.scm, gnu/tests/base.scm,
guix/scripts/system.scm, tests/services.scm: Likewise.
* doc/guix.texi (Service Reference): Adjust accordingly.

system: Make grub use <menu-entry> instead of <boot-parameters> again.

* gnu/system/grub.scm: Remove boot-parameters->menu-entry.
(grub-configuration): Don't use boot-parameters->menu-entry.
* gnu/system.scm (operating-system-bootcfg): Use menu-entry.
* guix/scripts/system.scm (reinstall-grub): Use profile-grub-entries.
(perform-action): Use profile-grub-entries.

scripts: system: Introduce profile-boot-parameters.

* guix/scripts/system.scm (profile-boot-parameters): New variable.
(reinstall-grub): Use profile-boot-parameters.
(perform-action): Use profile-boot-parameters.

Follow-up to 2e58e05bb68d4b747882cfa2b460b132d456f54a.

scripts: system: Rename grub? and  install-grub? to bootloader? and install-bootloader?.

* guix/scripts/system.scm (perform-action): Rename grub? to bootloader,
(%options): rename install-grub? to install-bootloader?,
(%default-options): ditto,
(process-action): reindent and rename grub? to bootloader?.