gnu: cross-base: Move phases to (gnu build cross-toolchain).

* gnu/packages/cross-base.scm (cross-gcc-arguments) <#:phases>: Use
'cross-gcc-build-phases', and move body cross-toolchain.scm.
(cross-gcc): Add #:imported-modules.  Add (gnu build cross-toolchain) to
 #:modules.
* gnu/build/cross-toolchain.scm: New file, with code from
'cross-gcc-arguments'.
* gnu/local.mk (GNU_SYSTEM_MODULES): Add it.

gnu: cross-base: Factorize list of cross environment variables.

* gnu/packages/cross-base.scm (cross-libc): Replace literal list of
environment variable names with %GCC-CROSS-INCLUDE-PATHS.
(cross-kernel-headers): Likewise.

gnu: ams-lv2: Remove CPU optimization flags on non-Intel hardware.

* gnu/packages/music.scm (ams-lv2)[arguments]: Add phase to remove
Intel specific CPU optimization flags when compiling on non-Intel
hardware.

gnu: python-sqlalchemy-utils: Update to 0.32.11.

* gnu/packages/python.scm (python-sqlalchemy-utils): Update to 0.32.11.

Signed-off-by: Marius Bakke <mbakke@fastmail.com>

gnu: Add python-sadisplay.

* gnu/packages/python.scm (python-sadisplay, python2-sadisplay): New variables.

Signed-off-by: Marius Bakke <mbakke@fastmail.com>

gnu: subversion: Update to 1.8.17.

* gnu/packages/version-control.scm (subversion): Update to 1.8.17.

gnu: make-bootstrap: Produce the correct %glibc-bootstrap-tarball for Hurd systems.

* gnu/packages/make-bootstrap.scm (%glibc-bootstrap-tarball): Make it a procedure.
  (%glibc-stripped): Make it a procedure and move the kernel specific part from
  here to ...
* guix/build/make-bootstrap.scm (make-stripped-libc): ... here. New file.
* Makefile.am (MODULES): Add it.

gnu: cross-kernel-headers: Remove propagated-inputs from xhurd-headers.

* gnu/packages/cross-base.scm (xhurd-headers)[propagated-inputs]: Remove them.

hydra: Add "i686-w64-mingw32" as a cross-compilation target.

* build-aux/hydra/gnu-system.scm (%cross-targets): Add "i686-w64-mingw32".
(hydra-jobs)[cross-jobs?](pointless?): New procedure.
Use it.

gnu: guile-2.0: support mingw.

* gnu/packages/guile.scm (guile-2.0): Support MinGW.

gnu: readline: support mingw.

* gnu/packages/patches/readline-7.0-mingw.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/readline.scm (readline): Support MinGW.

gnu: ncurses: support mingw.

* gnu/packages/ncurses.scm (ncurses): Support MinGW.

Co-Authored-By: Jan Nieuwenhuizen <janneke@gnu.org>

gnu: gmp: build shared library for mingw.

* gnu/packages/multiprecision.scm (gmp)[MINGW]: Use --enable-shared.

gnu: libunistring: support mingw: propagate libiconv if needed.

* gnu/packages/libunistring (libunistring): propagated-inputs: add
libiconv-if-needed.  Fixes unicode translation in MinGW.

gnu: Add function libiconv-if-needed.

* gnu/packages/base.scm (libiconv-if-needed): New function.

gnu: cross-base: Add i686-w64-mingw32 target.

* guix/utils.scm (mingw-target?): New function.
* gnu/packages/cross-base.scm (cross-gcc-snippet): New procedure
(cross-gcc): Use it.
(cross-gcc-arguments, cross-gcc-patches, cross-gcc): Support MinGW.
(native-libc, cross-newlib?): New functions.
(cross-libc): Use cross-newlib? to support MinGW.
(%gcc-include-paths, %gcc-cross-include-paths): New variables.

gnu: Add mingw-w64.

* gnu/packages/patches/gcc-4.9.3-mingw-gthr-default.patch,
gnu/packages/patches/mingw-w64-5.0rc2-gcc-4.9.3.patch,
gnu/packages/mingw.scm: New files.
* gnu/local.mk (dist_patch_DATA): Add the patches.
(GNU_SYSTEM_MODULES): Add mingw.scm.

doc: Correct example for 'wpa-supplicant-service-type'.

* doc/guix.texi (Networking Services): Change example to use
'wpa-supplicant-service-type'.

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

gnu: zynaddsubfx: Update to 3.0.1.

* gnu/packages/music.scm (zynaddsubfx): Update to 3.0.1.

gnu: libx264: Update to 20161205-2245.

* gnu/packages/video.scm (libx264): Update to 20161205-2245.
[source]: Use https.
[home-page]: Same.