gnu: Add mkbootimg.

* gnu/packages/android.scm (mkbootimg): New variable.

gnu: Add abootimg.

* gnu/packages/android.scm (abootimg): New variable.

system: Add Nintendo NES Classic Edition installer.

* gnu/bootloader/u-boot.scm (u-boot-nintendo-nes-classic-edition-bootloader):
New exported variable.
* gnu/packages/bootloaders.scm (u-boot-nintendo-nes-classic-edition):
New exported variable.
* gnu/system/install.scm (nintendo-nes-classic-edition-installation-os):
New exported variable.

system: make-u-boot-package: Replace underscores by dashes in package name.

* gnu/packages/bootloaders.scm (make-u-boot-package): Replace underscores by
dashes in package name.

system: Factor out embedded-installation-os.

* gnu/system/install.scm (embedded-installation-os): New variable.
(beaglebone-black-installation-os): Use it.
(a20-olinuxino-lime2-emmc-installation-os): Use it.
(a20-olinuxino-micro-installation-os): Use it.
(banana-pi-m2-ultra-installation-os): Use it.

system: Factor out agetty-default-service.

* gnu/system/install.scm (agetty-default-service): New variable.
(beaglebone-black-installation-os): Use it.
(a20-olinuxino-lime2-emmc-installation-os): Use it.
(a20-olinuxino-micro-installation-os): Use it.
(banana-pi-m2-ultra-installation-os): Use it.

system: Add A20 OLinuXino MICRO installer.

* gnu/bootloader/u-boot.scm (u-boot-a20-olinuxino-micro-bootloader): New
exported variable.
* gnu/packages/bootloaders.scm (u-boot-a20-olinuxino-micro): New exported
variable.
* gnu/system/install.scm (a20-olinuxino-micro-installation-os): New exported
variable.

system: Add A20 OLinuXino LIME2 installer.

* gnu/bootloader/u-boot.scm (u-boot-a20-olinuxino-lime2-bootloader): New
exported variable.
* gnu/packages/bootloaders.scm (u-boot-a20-olinuxino-lime2): New exported
variable.
* gnu/system/install.scm (a20-olinuxino-lime2-emmc-installation-os): New exported
variable.

gnu: wxsvg: Update to 1.5.12.

* gnu/packages/wxwidgets.scm (wxsvg): Update to 1.5.12.

gnu: video, xml: Fix typo.

* gnu/packages/video.scm (libva)[synopsis]: Fix ‘libary’ typo.
[description]: Use @dfn.
* gnu/packages/xml.scm (libebml): Likewise.

gnu: godot: Fix building on aarch64-linux.

* gnu/packages/game-development.scm (godot)[arguments]: Add a flag when
building for aarch64-linux to build without threads.

gnu: cross-base: Apply gcc 6 patch to gcc >= 6.

* gnu/packages/cross-base.scm (cross-gcc): Apply gcc 6 patch to gcc >= 6.

gnu: u-boot: Update to 2018.01.

* gnu/packages/bootloaders.scm (define-module): Import (gnu packages gcc).
(u-boot): Update to 2018.01.
[native-inputs]: Add swig.  Remove dtc.
(make-u-boot-package): Use gcc-7.

system: Add Banana Pi M2 Ultra installer.

* gnu/bootloader/u-boot.scm (u-boot-banana-pi-m2-ultra-bootloader): New
exported variable.
(install-allwinner-u-boot): New variable.
(u-boot-allwinner-bootloader): New variable.
* gnu/packages/bootloaders.scm (u-boot-banana-pi-m2-ultra): New exported
variable.
* gnu/system/install.scm (banana-pi-m2-ultra-installation-os): New exported
variable.

gnu: graphicsmagick: Update to 1.3.28 [‘security fixes’].

* gnu/packages/imagemagick.scm (graphicsmagick): Update to 1.3.28.

gnu: deutex: Update to 5.1.1.

* gnu/packages/games.scm (deutex): Update to 5.1.1.

gnu: lookingglass: Update to a10.

* gnu/packages/virtualization.scm (lookingglass): Update to a10.

gnu: libexif: Fix CVE-2016-6328.

* gnu/packages/patches/libexif-CVE-2016-6328.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/photo.scm (libexif)[source]: Use it.

gnu: perl-lingua-pt-stemmer: Update URL.

* gnu/packages/language.scm (perl-lingua-pt-stemmer)[source]: Use new
upstream URL.

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

gnu: escpr: Update to 1.6.18.

* gnu/packages/cups.scm (escpr): Update to 1.6.18.

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