Merge branch 'master' into python-tests

doc: Update patch submission instructions.

* doc/contributing.texi (Submitting Patches): Add paragraph on
guix-patches@gnu.org.

services: Add openvswitch-service-type.

* gnu/services/networking.scm (<openvswitch-configuration>): New record type.
(openvswitch-activation, openvswitch-shepherd-service): New procedures.
(openvswitch-service-type): New variable.
* doc/guix.texi (Networking Services): Document it.

gnu: Add dub-build-system.

* guix/build-system/dub.scm: New file.
* guix/build/dub-build-system.scm: New file.
* Makefile.am (MODULES): Add them.
* doc/guix.texi: Add section for dub-build-system.

import: Add stackage importer and updater.

* guix/import/stackage.scm: New file.
* guix/scripts/import/stackage.scm: New file.
* Makefile.am (MODULES): Add new files.
* guix/scripts/import.scm (importers): Add "stackage".
* guix/scripts/refresh.scm (%updaters): Add %stackage-updater.
* doc/guix.texi (Invoking 'guix import'): Document the importer.
  (Invoking 'guix refresh'): Add stackage to option --type valid values.
* guix/import/hackage.scm (guix-package->hackage-name, hackage-fetch,
  hackage-source-url, hackage-cabal-url, hackage-package?): Export them.

services: Add 'special-files-service-type'.

* gnu/build/activation.scm (activate-/bin/sh): Remove.
(activate-special-files): New procedure.
* gnu/services.scm (activation-script): Remove call to
'activate-/bin/sh'.
(special-files-service-type): New variable.
(extra-special-file): New procedure.
* gnu/services/base.scm (%base-services): Add SPECIAL-FILES-SERVICE-TYPE
instance.
* gnu/tests/base.scm (run-basic-test)[special-files]: New variables.
["special files"]: New test.

services: cuirass: Add load-path to cuirass configuration

* gnu/services/cuirass.scm (<cuirass-configuration>): Add load-path field.
(cuirass-shepherd-service): Honor it.
* doc/guix.texi (Continuous Integration): Document it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

doc: Discuss encrypted swap space.

* doc/guix.texi (Preparing for Installation): Provide an example of how to
  set up (encrypted) swap space using a swap file.
  (operating-system Reference)[swap-devices]: Clarify that swap files are
  supported, too.
  (Mapped Devices): Explain how to use a mapped device with a swap file to
  encrypt swap space.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

doc: Clarify that 'guix pull' can't be easily rolled back.

* doc/guix.texi (Invoking guix pull): Clarify that 'guix pull' can't be
  easily rolled back.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>

services: Make 'static-networking' extensible.

This allows users to statically define several interfaces.

* gnu/services/networking.scm (<static-networking>)[provision]
[name-servers]: Add default values.
(static-networking-shepherd-service)
(static-networking-etc-files)
(static-networking-shepherd-services): New procedures.
(static-networking-service-type): Change to extend both
SHEPHERD-ROOT-SERVICE-TYPE and ETC-SERVICE-TYPE.
(static-networking-service): Remove default value of #:provision.
Implement using 'simple-service'.
* gnu/services/base.scm (%base-services): Replace
'static-networking-service' call with 'service' form.
* doc/guix.texi (Networking Services): Update documentation.

doc: Fix typo.

* doc/guix.texi (ocaml-build-system): Replace ocaml with OCaml.

doc: Document ocaml-build-system.

* doc/guix.texi (Build Systems) [ocaml-build-system]: New definition.

doc: Fix typos.

Fixes a regression introduced in commit
f31f1acac2efb4bc6558b604a07b56f826423177.

Reported-by roptat on #guix.

* doc/guix.texi (Invoking guix build): Use "@@" instead of "@".

doc: Fix typos.

* doc/guix.texi: Use "@" for package specifications.

doc: Clarify "Installing GuixSD in a VM".

* doc/guix.texi (Installing GuixSD in a VM): Mention decompressing the
installation image.

doc: Fix networking instructions in "Installing GuixSD in a VM".

This is a followup to commit c8b543741f422ecf41e7635c6a1c40b3bd55947a.

* doc/guix.texi (Installing GuixSD in a VM): Fix typo.

doc: Add missing Upstart command for the binary installation.

Fixes <http://bugs.gnu.org/25551>.
Reported by Jason Self <jason@bluehome.net>.

* doc/guix.texi (Binary Installation): Add 'initctl
reload-configuration' command for Upstart.

doc: Add 'cups-configuration' example with 'hplip'.

* doc/guix.texi (Printing Services): Add example with 'hplip'.

doc: Mention the need of a BIOS boot partition when using GPT.

* doc/guix.text (Preparing for Installation)[Disk Partitioning]:
Mention the need of a BIOS boot partition when using GPT with the defualt
GRUB.

doc: Fix a typo in guix.texi.

* doc/guix.texi (Invoking guix environment): s/the use/use the/

Signed-off-by: Ludovic Courtès <ludo@gnu.org>