Merge branch 'master' into core-updates

More /gnu/store replacements.

* gnu/packages/gcc.scm (gcc-4.7): Change /nix/store in comment.
* gnu/system/vm.scm (operating-system-default-contents):
  Use (%store-prefix) instead of "/nix/store".
* guix/derivations.scm (derivation-path->output-path,
  derivation-path->output-paths): Change to /gnu/store in docstring.

Merge branch 'master' into core-updates

gnu: linux-initrd: Make the pseudo-tty device nodes.

* guix/build/linux-initrd.scm (make-essential-device-nodes): Create
  /dev/ptmx and /dev/pts.
* gnu/system/vm.scm (qemu-image): Umount /fs/dev/pts before /fs.

Merge branch 'master' into core-updates

Conflicts:
	gnu-system.am

gnu: vm: Remove '%demo-operating-system'.

* gnu/system/vm.scm (%demo-operating-system): Remove.
  (system-qemu-image, system-qemu-image/shared-store,
  system-qemu-image/shared-store-script): Adjust accordingly.

gnu: Introduce the (gnu services ...) modules.

* gnu/system/dmd.scm: Remove file.  Move contents to...
* gnu/services.scm, gnu/services/base.scm, gnu/services/dmd.scm,
  gnu/services/networking.scm, gnu/services/xorg.scm: ... here.  New
  files.
* gnu/system.scm, gnu/system/vm.scm: Adjust accordingly.
* guix/scripts/system.scm (%user-module): Likewise.
* doc/guix.texi (Using the Configuration System): Likewise.
  (Defining Services): Likewise.

gnu: dmd: Add SLiM service.

* gnu/system/dmd.scm (xorg-service): Remove.
  (xorg-start-command, slim-service): New procedure.

gnu: dmd: Fix X font directory name in X service.

* gnu/system/dmd.scm (xorg-service)[xserver.conf]: Fix directory name in
  'FontPath' entry for FONT-ADOBE75DPI.

gnu: Move root's home directory to /root.

* gnu/system.scm (operating-system-derivation): Change root's
  'home-directory' to "/root".
* gnu/system/vm.scm (operating-system-default-contents): Add /root.

gnu: dmd: Use 'text-file*' when building Xorg's config file.

* gnu/system/dmd.scm (xorg-service)[xserver.conf]: Change to use
  'text-file*' instead of 'text-file'.
  Adjust body accordingly.  Remove now extraneous packages from the
  service's 'inputs' field.

gnu: vm: Create all the user directories.

* gnu/system/vm.scm (operating-system-default-contents)[user-directories]:
  New procedure.  Use it to create each user's home and GC root
  directories.

gnu: vm: Add /run/current-system and /bin/sh.

* gnu/system/vm.scm (operating-system-default-contents): Populate
  /run/current-system and create /bin/sh.
* gnu/system.scm (operating-system-profile-derivation,
  operating-system-profile-directory): New procedures.
  (operating-system-derivation): Use it.

gnu: Add preliminary Xorg service.

* gnu/system/dmd.scm (xorg-service): New procedure.

gnu: vm: Add support for running a VM that shares its store with the host.

* gnu/system/vm.scm (qemu-image): Check whether GUIX is #f.
  (operating-system-build-gid, operating-system-default-contents): New
  procedures.
  (system-qemu-image): Use 'operating-system-build-gid'.
  (system-qemu-image/shared-store,
  system-qemu-image/shared-store-script): New procedures.
* gnu/system.scm: Add missing exports.

gnu: linux-initrd: Allow the root file system to be volatile.

* gnu/system/linux-initrd.scm (qemu-initrd): Add 'volatile-root?'
  parameter.
* guix/build/linux-initrd.scm (boot-system): Likewise.  Honor it.

gnu: linux-initrd: Recognize 9p file systems.

* gnu/system/linux-initrd.scm (qemu-initrd)[virtio-9p-modules]: New
  variable.
  [linux-modules]: Append VIRTIO-9P-MODULES when a 9p file system is in
  MOUNTS.
* guix/build/linux-initrd.scm (mount-qemu-9p): New procedure.
  (boot-system): Recognize '9p' in MOUNTS, and use 'mount-qemu-9p'.

gnu: linux-initrd: Match kernel module file names exactly.

* gnu/system/linux-initrd.scm (expression->initrd)[string->regexp]: New
  procedure.  Use it in the call to 'find-files'.

gnu: linux-initrd: Properly distinguish between /dev/sda* and /dev/vda*.

* guix/build/linux-initrd.scm (make-essential-device-nodes): Rename
  devices with major = 8 to /dev/sda*.  Make /dev/vda* devices.
* gnu/system/vm.scm (qemu-image): Change '/dev/vda' to '/dev/sda'.
* gnu/system.scm (operating-system-derivation): Likewise.

gnu: vm: Run QEMU with '-enable-kvm'.

* gnu/system/vm.scm (expression->derivation-in-linux-vm): Pass QEMU
  '-enable-kvm'.