gnu: Add scrot.

* gnu/packages/scrot.scm: New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add it.

gnu: Add giblib.

* gnu/packages/image.scm (giblib): New variable.

gnu: Add imlib2.

* gnu/packages/image.scm (imlib2): New variable.

gnu: libtoxcore: Update to 1.0.0.

* gnu/packages/crypto.scm (libsodium): Update version and change home-page.

Introduce the 'GUIX_PACKAGE_PATH' environment variable.

* gnu/packages.scm (%package-module-path): Honor $GUIX_PACKAGE_PATH.
* test-env.in: Unset 'GUIX_PACKAGE_PATH'.
* tests/guix-package.sh: Test it.
* doc/guix.texi (Package Modules): Document it.

packages: Add '%package-module-search-path'.

* gnu/packages.scm (%package-module-path): New variable.
  (all-package-modules): New procedure.
  (fold-packages): Use it instead of 'package-modules'.

packages: Generalize package module search.

* gnu/packages.scm (%distro-root-directory): New variable.
  (%distro-module-directory): Remove.
  (package-files): Rename to...
  (scheme-files): ... this.  Return absolute file names, not stripped.
  (file-name->module-name): New procedure.
  (package-modules): Add 'directory' and 'sub-directory' parameters.
  Rewrite accordingly.
  (fold-packages): Adjust 'package-modules' call accordingly.

gnu: maxima: Update to 5.34.1 and add dependencies.

* gnu/packages/maths.scm (maxima): Update to 5.34.1 which fixes a bug in
  the plotting capabilities present in the previous version.  Add Gnuplot
  and Tcl/Tk to 'inputs'.

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

Use #:prefix instead of #:renamer with 'symbol-prefix-proc'.

* gnu/packages/abiword.scm, gnu/packages/admin.scm, gnu/packages/aidc.scm,
  gnu/packages/backup.scm, gnu/packages/bittorrent.scm,
  gnu/packages/boost.scm, gnu/packages/compression.scm,
  gnu/packages/cryptsetup.scm, gnu/packages/curl.scm,
  gnu/packages/cyrus-sasl.scm, gnu/packages/dc.scm, gnu/packages/emacs.scm,
  gnu/packages/fonts.scm, gnu/packages/fontutils.scm, gnu/packages/geeqie.scm,
  gnu/packages/ghostscript.scm, gnu/packages/gimp.scm,
  gnu/packages/gkrellm.scm, gnu/packages/gl.scm, gnu/packages/glib.scm,
  gnu/packages/gnome.scm, gnu/packages/gnunet.scm, gnu/packages/gnupg.scm,
  gnu/packages/gnutls.scm, gnu/packages/gnuzilla.scm, gnu/packages/gsasl.scm,
  gnu/packages/gtk.scm, gnu/packages/gv.scm, gnu/packages/image.scm,
  gnu/packages/indent.scm, gnu/packages/inkscape.scm,
  gnu/packages/lesstif.scm, gnu/packages/links.scm, gnu/packages/lisp.scm,
  gnu/packages/lsh.scm, gnu/packages/lsof.scm, gnu/packages/maths.scm,
  gnu/packages/mp3.scm, gnu/packages/openssl.scm, gnu/packages/ots.scm,
  gnu/packages/pciutils.scm, gnu/packages/pcre.scm, gnu/packages/pdf.scm,
  gnu/packages/pulseaudio.scm, gnu/packages/python.scm, gnu/packages/slim.scm,
  gnu/packages/ssh.scm, gnu/packages/texlive.scm, gnu/packages/vim.scm,
  gnu/packages/vpn.scm, gnu/packages/web.scm, gnu/packages/wv.scm,
  gnu/packages/xiph.scm, gnu/packages/xml.scm, gnu/packages/xorg.scm,
  gnu/packages/yasm.scm, gnu/packages/zip.scm,
  guix/build/cmake-build-system.scm, guix/build/perl-build-system.scm,
  guix/build/python-build-system.scm, guix/download.scm: Replaces uses of
  #:renamer and 'symbol-prefix-proc' with #:prefix.

gnu: gtk+: Disable tests on mips64el-linux.

* gnu/packages/gtk.scm (gtk+): Disable tests on mips64el-linux.

gnu: gtk+: Remove dependency on Xorg server on mips64el-linux.

Reported by Mark H. Weaver.

* gnu/packages/gtk.scm (gtk+)[native-inputs]: Remove XORG-SERVER on
  mips64el-linux.

services: Add 'bitlbee-service'.

* gnu/services/networking.scm (bitlbee-service): New procedure.
* doc/guix.texi (Networking Services): Document it.

gnu: xf86-input-synaptics: Allow building with libc 2.20.

* gnu/packages/patches/xf86-input-synaptics-glibc-2.20.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/xorg.scm (xf86-input-synaptics): Use it.  Improve
  synopsis and description.

gnu: node: Add 'which' as an input.

* gnu/packages/node.scm (node)[native-inputs]: Add WHICH.

gnu: xorg: Remove xf86-input-vmmouse.

* gnu/packages/xorg.scm (xf86-input-vmmouse): Remove.  This driver
  implement the mouse protocol of a proprietary emulator.
* gnu/services/xorg.scm (xorg-start-command): Remove reference.

gnu: linux-libre: Work around GCC 4.8.3 ICE.

* gnu/packages/linux.scm (linux-libre)[inputs]: New field.

system: Add Patch to '%base-packages'.

* gnu/system.scm (%base-packages): Add PATCH.

Merge branch 'core-updates'

linux-initrd: Adjust VM code and doc to new 'base-initrd' signature.

This fixes regressions introduced in de1c158 ("system: Add support for
boot-time mapped devices.").

* doc/guix.texi (Initial RAM Disk): Adjust example with custom use of
  'base-initrd'.  Document #:mapped-devices parameter of 'base-initrd'.
* gnu/system/vm.scm (system-disk-image, system-qemu-image,
  virtualized-operating-system): Adjust call to 'base-initrd' to new
  signature.

gnu: perl-tk: Build sequentially.

Fixes <http://bugs.gnu.org/18262>.

* gnu/packages/tcl.scm (perl-tk)[arguments]: Add #:parallel-build? #f.