gnu: webkitgtk: Update to 2.16.3 [fixes CVE-2017-{2496,2510,2539}].

* gnu/packages/webkit.scm (webkitgtk): Update to 2.16.3.

build-system: gnu: Fix cross-gcc call.

This is a follow-up to 7b3318e34f4e2743254a88b908859901db960e9a.

* guix/build-system/gnu.scm (standard-cross-packages): Use keyword arguments
in cross-gcc call.

gnu: Add ocaml-ppx-jane.

* gnu/packages/ocaml.scm (ocaml-ppx-jane): New variable.

gnu: Add ocaml-ppx-expect.

* gnu/packages/ocaml.scm (ocaml-ppx-expect): New variable.

gnu: Add ocaml-re.

* gnu/packages/ocaml.scm (ocaml-re): New variable.

gnu: Add ocaml-ppx-fields-conv.

* gnu/packages/ocaml.scm (ocaml-ppx-fields-conv): New variable.

gnu: Add ocaml-ppx-sexp-message.

* gnu/packages/ocaml.scm (ocaml-ppx-sexp-message): New variable.

gnu: Add ocaml-ppx-custom-printf.

* gnu/packages/ocaml.scm (ocaml-ppx-custom-printf): New variable.

gnu: Add ocaml-ppx-fail.

* gnu/packages/ocaml.scm (ocaml-ppx-fail): New variable.

gnu: Add ocaml-ppx-bin-prot.

* gnu/packages/ocaml.scm (ocaml-ppx-bin-prot): New variable.

gnu: Add ocaml-ppx-pipebang.

* gnu/packages/ocaml.scm (ocaml-ppx-pipebang): New variable.

gnu: Add ocaml-ppx-sexp-value.

* gnu/packages/ocaml.scm (ocaml-ppx-sexp-value): New variable.

pull: Catch '&missing-dependency-error' raised by 'source-module-closure'.

Fixes <http://bugs.gnu.org/26987>.
Reported by Mathieu Othacehe <m.othacehe@gmail.com>.

* guix/build/pull.scm (depends-on-guile-ssh?): Remove.
(has-all-its-dependencies?): New procedure.
(build-guix): Use it to filter source files.

modules: Raise an error when a dependency could not be found.

* guix/modules.scm (&missing-dependency-error): New error condition.
(source-module-dependencies): Raise it when 'search-path' returns #f.
* tests/modules.scm ("&missing-dependency-error"): New test.

base64: Turn into a regular Guile module.

* guix/base64.scm: Replace 'library' form with 'define-module'.

gnu: sunxi-tools: Build armhf target tools.

* gnu/packages/admin.scm (sunxi-tools)
[native-inputs]: Add cross-gcc, cross-libc.
[arguments]: Add "set-environment-up" phase.
Replace "build" phase.
Add "build-armhf" phase.
Update make-flags.

gnu: Add python-behave-web-api.

Fixes <http://bugs.gnu.org/26906>.

* gnu/packages/python.scm (python-behave-web-api, python2-behave-web-api):
New variables.

gnu: Enable python-parse-type tests.

Fixes <http://bugs.gnu.org/26900>.

* gnu/packages/python.scm (python-parse-type)[arguments]: Enable tests.
Add phase "patch-tests".
[native-inputs]: Add python-pytest, python-pytest-runner.
[properties]: Add python2-variant.
(python2-parse-type): New variable.

gnu: warzone2100: Use modular Qt.

* gnu/packages/games.scm (warzone2100)[inputs]: Remove qt, add qtbase and
qtscript.
[arguments]: Add build phase "patch-for-qt5.8".

gnu: tiled: Use modular Qt.

* gnu/packages/game-development.scm (tiled)[inputs]: Remove qt; add qtbase and
qtsvg.
[native-inputs]: Add qttools.
[arguments]: Override LRELEASE in translations.pro.