Merge branch 'master' into staging

gnu: Add raul-devel.

* gnu/packages/audio.scm (raul-devel): New variable.

gnu: lvtk: Build UI library.

* gnu/packages/audio.scm (lvtk)[inputs]: Add gtkmm-2.
[arguments]: Pass "-std=c++11" flag.

gnu: ardour: Update to 5.5.

* gnu/packages/audio.scm (ardour): Update to 5.5.

Merge branch 'master' into staging

Merge branch 'python-build-system'.

Merge branch 'master' into python-build-system

gnu: lv2: Update to 1.14.0.

* gnu/packages/audio.scm (lv2): Update to 1.14.0.

gnu: Add threaded variants of fftw and fftwf for Ardour and mod-host.

* gnu/packages/algebra.scm (fftw-with-threads, fftwf-with-threads): New
variables.
* gnu/packages/audio.scm (ardour)[inputs]: Replace "fftw" and "fftwf"
with "fftw-with-threads" and "fftwf-with-threads", respectively.
* gnu/packages/music.scm (mod-host)[inputs]: Likewise.

Merge branch 'master' into python-build-system

gnu: ir: Use archived tarball and home page.

* gnu/packages/audio.scm (ir)[source]: Use a list of archive mirrors.
[home-page]: Link to an Internet Archive snapshot.

gnu: ir: Use ‘modify-phases’ syntax.

* gnu/packages/audio.scm (ir)[arguments]: Use ‘modify-phases’.

Merge branch 'master' into staging

gnu: Add espeak.

* gnu/packages/audio.scm (espeak): New variable.

gnu: qsynth: Update to 0.4.3.

* gnu/packages/audio.scm (qsynth): Update to 0.4.3.

gnu: Fix python inputs, part 7: Ensure python-cython is a native-input.

* gnu/packages/audio.scm (python-pyliblo): [inputs] Move python-cyton to
  [native-inputs].
* gnu/packages/bioinformatics.scm (python2-pybedtools): dito.
* gnu/packages/music.scm (beast, python-pyportmidi): dito.
* gnu/packages/python.scm (python2-fastlmm, python-kivy): dito.

Merge branch 'core-updates'

gnu: Add faust-2.

* gnu/packages/audio.scm (faust-2): New variable.

Merge branch 'master' into core-updates

gnu: xmp: Update to 4.1.0.

* gnu/packages/audio.scm (xmp): Update to 4.1.0.