gnu: gnupg@2.0: Add the 'gpg' and 'gpgv' commands.

* gnu/packages/gnupg.scm (gnupg-2.0)[arguments]: Add
'rename-v2-commands' phase.

gnu: gnupg@2.0: Fix typo.

* gnu/packages/gnupg.scm (gnupg@2.0)[arguments]: Fix typo that prevented
gnupg from building.

This is a follow up to 6b547d22952fb30c4419d4f81545353907ab398d.

gnu: exiv2: Update source url.

* gnu/packages/geeqie.scm (exiv2)[source]: Update url.

lint: 'inputs-should-be-native' checks for intltool, itstool and glib:bin.

* guix/scripts/lint.scm (check-inputs-should-be-native): Warn when intltool,
itstool or glib:bin isn't a native-input.
* tests/lint.scm (inputs: glib:bin is probably a native input): Add test.

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

doc: Point out preference of message format.

* doc/contributing.texi (Submitting Patches): Includes a note on
preference of plain text messages with either inline or MIME attachments
and advise contributers to pay attention if their email client breaks the
patches.

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

doc: Explain that contributors can use a pseudonym.

Suggested by ng0 <ng0@we.make.ritual.n0.is>.

* doc/contributing.texi (Contributing): Explain that using a legal name
is not required.

doc: gnupg@2.0: Use 'modify-phases'.

* gnu/packages/gnupg.scm (gnupg-2.0)[arguments]: Use 'modify-phases'.

doc: Explain how to set up Git for signing.

* HACKING (Commit Access): Give instructions on how to set up Git for
signing.

gnu: icecat: Disable parallel build.

* gnu/packages/gnuzilla.scm (icecat)[arguments]: Disable parallel build.

download: Add SourceForge load balancer.

* guix/download.scm (%mirrors)[sourceforge]: Add canonical load balancer for
sourceforge.net.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: icecat: Update to 38.8.0-gnu2.

* gnu/packages/gnuzilla.scm (icecat): Update to 38.8.0-gnu2.

gnu: openssh: Fix CVE-2016-6210.

* gnu/packages/ssh.scm (openssh)[source]: Add patches
openssh-CVE-2016-6210-1.patch, openssh-CVE-2016-6210-2.patch,
openssh-CVE-2016-6210-3.patch.
* gnu/packages/patches/openssh-CVE-2016-6210-1.patch: New file.
* gnu/packages/patches/openssh-CVE-2016-6210-2.patch: New file.
* gnu/packages/patches/openssh-CVE-2016-6210-3.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register them.

gnu: pspp: Update to 0.10.2.

* gnu/packages/statistics.scm (pspp): Update to 0.10.2.

gnu: python-iso8601: Update to 0.1.11.

* gnu/packages/python.scm (python-iso8601): Update to 0.1.11.

gnu: iniparser: Use 'modify-phases'.

* gnu/packages/samba.scm (iniparser)[arguments]: Use 'modify-phases'
syntax.

gnu: iniparser: Update to 4.0.

* gnu/packages/samba.scm (iniparser): Update to 4.0.
[source]: Download from Github.
[arguments]: Define 'gcc' in Makefiles.

gnu: python-waf: Update to 1.9.1.

* gnu/packages/python.scm (python-waf): Update to 1.9.1.

gnu: mpv: Use packaged waf.

* gnu/packages/video.scm (mpv)[inputs]: Remove externally downloaded waf
package and use packaged python-waf.

gnu: wxwidgets: Update source URL.

* gnu/packages/wxwidgets.scm (wxwidgets, wxwidgets-2): Update source URL.

gnu: git: Update to 2.9.2.

* gnu/packages/version-control.scm (git): Update to 2.9.2.
(git-manpages)[source]: Update hash.