Merge branch 'core-updates'

gnu: coreutils: Update to 8.23.

* gnu/packages/patches/coreutils-skip-nohup.patch: Remove.
* gnu-system.am (dist_patch_DATA): Remove coreutils-skip-nohup.patch.
* gnu/packages/patches/coreutils-dummy-man.patch: Adapt for 8.23.
* gnu/packages/base.scm (coreutils): Update to 8.23.

Merge branch 'core-updates'

gnu: coreutils: Patch 'Makefile.in', not 'local.mk'.

* gnu/packages/patches/coreutils-dummy-man.patch: Patch 'Makefile.in',
  not 'local.mk'; the latter otherwise requires Automake to regenerate
  the build system.

gnu: coreutils: Attempt to really fix cross-compilation.

* gnu/packages/patches/coreutils-dummy-man.patch: Directly take the
  patch from <http://git.yoctoproject.org/cgit.cgi/poky/plain/meta/recipes-core/coreutils/coreutils-8.22/fix-for-dummy-man-usage.patch>.

gnu: coreutils: Fix cross-compilation issue with 'dummy-man'.

This should work around the bug described at
<http://git.yoctoproject.org/cgit.cgi/poky/plain/meta/recipes-core/coreutils/coreutils-8.22/fix-for-dummy-man-usage.patch>.

* gnu/packages/base.scm (coreutils)[patches]: Add
  'coreutils-dummy-man.patch'.
  [native-inputs]: Don't pass PERL when (%current-target-system) is
  true.
* gnu/packages/patches/coreutils-dummy-man.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.