gnu: Add emacs-nginx-mode.

* gnu/packages/emacs.scm (emacs-nginx-mode): New variable.

Signed-off-by: Alex Kost <alezost@gmail.com>

gnu: Add emacs-evil.

* gnu/packages/emacs.scm (emacs-evil): New variable.

Co-authored-by: Alex Kost <alezost@gmail.com>

gnu: Add emacs-goto-chg.

* gnu/packages/emacs.scm (emacs-goto-chg): New variable.

Co-authored-by: Alex Kost <alezost@gmail.com>

Revert "guix: python-build-system: Fix an outdated comment."

This reverts commit 635a7af45d6e2105ad65d1a9531126cc232a2a50.

guix: python-build-system: Fix an outdated comment.

The python-build-system uses phases the build and install, but not
configure. So the old comment was plain wrong since Sept. 2013, when the build
phase has been added.

gnu: python-pathlib: Update description.

* gnu/packages/python.scm (python-pathlib, python2-pathlib): Update
  description.

gnu: python-keyring: Update home-page url.

* gnu/packages/python.scm (python-keyring, python2-keyring): Update home-page
  url.

gnu: python-pylockfile: Update home-page url.

* gnu/packages/python.scm (python-pylockfile, python2-pylockfile): Update
  home-page url.

gnu: python-zope-testing: Strip byte-code and backup-files from source.

* gnu/package/python.scm (python-zope-testing, python2-zope-testing)[source]:
  Add snippet to strip byte-code and backup-files.

gnu: python-pytest-xdist: Remove python byte-code files from source.

* gnu/packages/python.scm (python-pytest-xdist,
  python2-pytest-xdist)[source]: Add snippet.

gnu: python2-pytest-runner, python2-msgpack: Remove duplicate definitions.

* gnu/packages/python.scm (python2-pytest-runner): Was defined twice, remove
  duplicate definition. (python2-msgpack): Was defined twice, but differently,
  remove the obviously wrong second definition.

git: webkitgtk: Update to 2.14.1.

* gnu/packages/webkit.scm (webkitgtk): Update to 2.14.1.

gnu: linux-libre@4.1: Update to 4.1.34.

* gnu/packages/linux.scm (linux-libre-4.1): Update to 4.1.34.

gnu: graphicsmagick: Update to 1.3.25-1-56c8cae [security fixes].

Fixes CVE-2016-7800, CVE-2016-7996, CVE-2016-7997, and several other flaws.

* gnu/packages/imagemagick.scm (graphicsmagick): Update to 1.3.25-1-56c8cae.
[source]: Change method from 'url-fetch' to 'hg-fetch'.  Add 'file-name'.

gnu: imagemagick: Disable tests.

* gnu/packages/imagemagick.scm (imagemagick)[arguments]: Disable tests.

gnu: imagemagick: Update to 6.9.6-2 [Fixes CVE-2016-{7799,7906}].

* gnu/packages/imagemagick.scm (imagemagick): Update to 6.9.6-2.

gnu: ghostscript-with-x: Avoid inheriting replacement field.

This is a followup to commit 1de17a648fa631f0074d315bfff0716220ce4880.

* gnu/packages/ghostscript.scm (ghostscript/fixed)[replacement]:
Override inherited value.

gnu: ghostscript: Fix CVE-2013-5653 and CVE-2016-{7976,7978,7979,8602}.

* gnu/packages/patches/ghostscript-CVE-2013-5653.patch,
gnu/packages/patches/ghostscript-CVE-2016-7976.patch,
gnu/packages/patches/ghostscript-CVE-2016-7978.patch,
gnu/packages/patches/ghostscript-CVE-2016-7979.patch,
gnu/packages/patches/ghostscript-CVE-2016-8602.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/ghostscript.scm (ghostscript)[replacement]: New field.
(ghostscript/fixed): New variable.
(ghostscript/x): Inherit 'ghostscript/fixed'.

doc: Add guide on how to specify dependencies for Python packages.

* doc/guix.texi (Python Modules): New sub-subsection "Specifying
Dependencies".

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

gnu: Add hdf4

* gnu/packages/maths.scm (hdf4, hdf4-alt): New variables.
* gnu/packages/patches/hdf4-reproducibility.patch: New file.
* gnu/packages/patches/hdf4-shared-fortran.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add patches.

Co-Authored-By: Jeremy Robst <jpro@bas.ac.uk>

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