gnu: Add emacs-rainbow-mode.

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

gnu: libconfuse: Update to 3.1.

* gnu/packages/wm.scm (libconfuse): Update to 3.1.
[source, home-page]: Change to new home page.

gnu: mcelog: Update to 151.

* gnu/packages/linux.scm (mcelog): Update to 151.

gnu: arm-none-eabi-toolchain: Include libstdc++.

* gnu/packages/embedded.scm (arm-none-eabi-toolchain)[propagated-inputs]: Add
libstdc++.

gnu: arm-none-eabi-toolchain: Provide union of all inputs at the output.

* gnu/packages/embedded.scm (arm-none-eabi-toolchain)[arguments]: Make the
union of all inputs available at the output.

gnu: Add libstdc++-arm-none-eabi.

* gnu/packages/embedded.scm (make-libstdc++-arm-none-eabi): New procedure.

gnu: avr-gcc-4.9: Use gcc-4.9 as base compiler.

* gnu/packages/avr.scm (avr-gcc-4.9): Pass gcc-4.9 to "cross-gcc".

gnu: Allow overriding of xgcc package in cross-gcc.

* gnu/packages/cross-base.scm (cross-gcc-arguments): Take extra "xgcc"
argument.
(cross-gcc): Use keyword arguments; take optional "xgcc" argument.
* gnu/packages/embedded.scm (gcc-arm-none-eabi-4.9, propeller-gcc, gcc-vc4):
Use keyword arguments.
* gnu/packages/avr.scm (avr-gcc-4.9): Likewise.

gnu: brdf-explorer: Update to 1.0.0-1.5b2cd46f3.

* gnu/packages/graphics.scm (brdf-explorer): Update to 1.0.0-1.5b2cd46f3.
[source]: Use git-fetch method.
[arguments]: Adjust configure phase.
[native-inputs]: Replace qt with qttools.
[inputs]: Replace qt with qtbase.

gnu: libtasn1: Fix CVE-2017-6891.

* gnu/packages/patches/libtasn1-CVE-2017-6891.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/tls.scm (libtasn1)[replacement]: New field.
(libtasn1/fixed): New variable.

gnu: sane-backends-minimal: Run most tests.

* gnu/packages/scanner.scm (sane-backends-minimal)[arguments]: Add a
‘disable-failing-tests’ phase to do just that, and run the rest.

gnu: sane-backends-minimal, sane-backends: Update to 1.0.27.

* gnu/packages/scanner.scm (sane-backends-minimal): Update to 1.0.27.
[source]: Use (what should be) a more stable download URI.

gnu: suil: Use qtbase instead of qt-4.

* gnu/packages/audio.scm (suil)[inputs]: Replace qt-4 with qtbase.
[arguments]: Add configure flags that are needed for qtbase.

gnu: qtractor: Use modular Qt.

* gnu/packages/music.scm (qtractor)[inputs]: Remove qt, add qtbase and
qtx11extras.
[native-inputs]: Add qttools.

gnu: qtractor: Update to 0.8.2.

* gnu/packages/music.scm (qtractor): Update to 0.8.2.

gnu: python-pyasn1: Update to 0.2.3.

* gnu/packages/python.scm (python-pyasn1, python2-pyasn1): Update to 0.2.3.

gnu: python-idna: Update to 2.5.

* gnu/packages/python.scm (python-idna, python2-idna): Update to 2.5.
[source]: Use pypi-uri.

gnu: asn1c: Update to 0.9.28.

* gnu/packages/tls.scm (asn1c): Update to 0.9.28.

gnu: gnome-themes-standard: Update to 3.22.3.

* gnu/packages/gnome.scm (gnome-themes-standard): Update to 3.22.3.

gnu: clutter-gst: Update to 3.0.24.

* gnu/packages/gnome.scm (clutter-gst): Update to 3.0.24.