emacs: Enable 'guix-build-log-minor-mode' in shell buffers.

* emacs/guix-build-log.el (guix-build-log-minor-mode-activate): New variable.
  (guix-build-log-minor-mode-activate-maybe): New function.
* emacs/guix-init.el: Add it to 'shell-mode-hook'.
* doc/emacs.texi (Emacs Build Log): Mention it.

emacs: Enable 'guix-build-log-mode' for build log files.

* emacs/guix-build-log.el (auto-mode-alist): Add 'guix-build-log-mode'
  to 'auto-mode-alist'.

emacs: Add completions for '--type' option of 'refresh' popup.

* guix/scripts/refresh.scm: Export '%updaters'.
* emacs/guix-main.scm (refresh-updater-names): New procedure.
* emacs/guix-base.el (guix-refresh-updater-names): New function.
* emacs/guix-read.el (guix-read-refresh-updater-names,
  guix-read-refresh-updater-names-string): New functions.
* emacs/guix-command.el (guix-command-improve-refresh-argument): Use
  'guix-read-refresh-updater-names-string'.

emacs: Disable minor modes in 'guix-build-log-mode'.

* emacs/guix-build-log.el (guix-build-log-mode-hook): Remove
  'compilation-shell-minor-mode' as it is slow on big buffers, and
  'view-mode' as it rebinds too many keys.
  (guix-build-log-mode-map): Add "c" and "v" key bindings for the
  removed minor modes.

emacs: Add key bindings for 'guix-build-log-minor-mode'.

* emacs/guix-build-log.el (guix-build-log-mode-map): Move keys to ...
  (guix-build-log-common-map): ...here.  New variable.
  (guix-build-log-minor-mode-map): New variable.
  (guix-build-log-minor-mode): Use it.
* doc/emacs.texi (Emacs Build Log): Document it.

emacs: Add shell completions for 'guix refresh --type'.

* emacs/guix-pcomplete.el (guix-pcomplete-refresh-updaters): New function.
  (guix-pcomplete-complete-option-arg): Complete '-t/--type' option for
  'guix refresh' command.

Merge branch 'master' into dbus-update

services: Add 'modify-services'.

* gnu/services.scm (%modify-service, modify-services): New macros.
* gnu/services/base.scm (mingetty-service-type, guix-service-type):
  Export.
* emacs/guix-devel.el (guix-devel-keywords): Add 'modify-services'.
  Ditto in 'guix-devel-scheme-indent' call.
* doc/guix.texi (Using the Configuration System): Give an example of
  'modify-services'.
  (Service Reference): Document it.

emacs: Use 'switch-to-generation*'.

This is a followup to commit 06d45f4566469364b4c1fe6d3c71ecf58f5d4838.

* emacs/guix-base.el (guix-switch-to-generation): Replace
  'switch-to-generation' with 'switch-to-generation*'.

emacs: Add "Packages" option for 'guix challenge' popup.

* emacs/guix-command.el (guix-command-rest-argument): Add "challenge".

emacs: Add shell completions for 'guix challenge'.

* emacs/guix-pcomplete.el (guix-pcomplete-complete-command-arg): Add
  "challenge" to complete package names for it.

Merge branch 'master' into dbus-update

emacs: devel: Add indentation rules for 'modify-phases' keywords.

* emacs/guix-devel.el: Add indentation rules for 'modify-phases' keywords.
  (guix-devel-indent-modify-phases-keyword,
  guix-devel-indent-modify-phases-keyword-1,
  guix-devel-indent-modify-phases-keyword-2): New functions.

emacs: config: Use "emacs-config-" prefix for constants.

* emacs/guix-config.el.in (guix-emacs-interface-directory,
  guix-state-directory): Rename to ...
  (guix-config-emacs-interface-directory, guix-config-state-directory):
  ...this.
  (guix-config-guile-program): New constant.
  (guix-guile-program): Move to ...
* emacs/guix-external.el (guix-guile-program): ...here.  Make it a
  'defcustom'.
* emacs/guix-profiles.el (guix-default-profile): Use
  'guix-config-state-directory'.
* emacs/guix-backend.el (guix-load-path): Use
  'guix-config-emacs-interface-directory'.

build: Set DOT_USER_PROGRAM for Emacs interface.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* configure.ac: Set DOT_USER_PROGRAM variable.
* emacs/guix-config.el.in (guix-config-dot-program): New constant.
* emacs/guix-external.el (guix-dot-program): Use it.

Merge branch 'master' into dbus-update

emacs: devel: Highlight Guix keywords.

* emacs/guix-devel.el (guix-devel-keywords): New constant.
  (guix-devel-font-lock-keywords): Use it.

emacs: Improve file names of generated graphs.

Suggested by Ludovic Courtès <ludo@gnu.org>.

* emacs/guix-external.el (guix-png-file-name): Change prefix of a file
  name to "guix-emacs-graph-" to avoid possible conflicts.

emacs: Add "View graph" actions to system graph commands.

* emacs/guix-command.el (guix-command-additional-execute-arguments,
  guix-command-special-executors): Add "View graph" actions for
  'dmd-graph' and 'extension-graph' commands.

emacs: Disambiguate "d" key in 'system' popup.

* emacs/guix-command.el (guix-command-improve-system-argument): Use "D"
  key for 'disk-image' action (leave "d" for 'dmd-graph').