gnu: xcursor-themes: Install data into package output directory.

* gnu/packages/xorg.scm (xcursor-themes): Install icons into output directory
    instead of libxcursor.

gnu: Add python2-pyicu.

* gnu/packages/python.scm (python2-pyicu): New variable.

gnu: Add python-simplejson, python2-simplejson.

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

gnu: python2-pysqlite: Fix 'license'.

* gnu/packages/python.scm (python2-pysqlite): Refer to (@ (guix
  licenses) zlib), not to the same-named package.

gnu: QEMU images boots into dmd.

* gnu/system/dmd.scm: New file.
* gnu/system/vm.scm (system-qemu-image): Define dmd services.
  [populate]: Make var/log and etc/group.
  [boot]: Execute dmd directly.
  Add dmd and etc-group as inputs; add the inputs of dmd services.
* gnu-system.am (GNU_SYSTEM_MODULES): Add gnu/system/dmd.scm.

gnu: Add GNU dmd.

* gnu/packages/system.scm (dmd): New variable.

derivations: 'derivation' and related procedures return a single value.

* guix/derivations.scm (derivation->output-path,
  derivation->output-paths): New procedures.
  (derivation-path->output-path): Use 'derivation->output-path'.
  (derivation-path->output-paths): Use 'derivation->output-paths'.
  (derivation): Accept 'derivation?' objects as inputs.  Return a single
  value.
  (build-derivations): New procedure.
  (compiled-modules): Use 'derivation->output-paths'.
  (build-expression->derivation)[source-path]: Add case for when the
  input matches 'derivation?'.
  [prologue]: Accept 'derivation?' objects in INPUTS.
  [mod-dir, go-dir]: Use 'derivation->output-path'.
* guix/download.scm (url-fetch): Adjust to the single-value return.
* guix/packages.scm (package-output): Use 'derivation->output-path'.
* guix/scripts/build.scm (guix-build): When the argument is
  'derivation-path?', pass it through 'read-derivation'.
  Use 'derivation-file-name' to print out the .drv file names, and to
  register them.  Use 'derivation->output-path' instead of
  'derivation-path->output-path'.
* guix/scripts/package.scm (roll-back): Adjust to the single-value
  return.
  (guix-package): Use 'derivation->output-path'.
* guix/ui.scm (show-what-to-build): Adjust to deal with 'derivation?'
  objects instead of .drv file names.
* gnu/system/grub.scm (grub-configuration-file): Use
  'derivation->output-path' instead of 'derivation-path->output-path'.
* gnu/system/vm.scm (qemu-image, system-qemu-image): Likewise.
* tests/builders.scm, tests/derivations.scm, tests/packages.scm,
  tests/store.scm, tests/union.scm: Adjust to the new calling
  convention.
* doc/guix.texi (Defining Packages, The Store, Derivations): Adjust
  accordingly.

gnu: dbus: Add dependency on libX11.

* gnu/packages/glib.scm: Use #:export instead of 'define-public'.
  (dbus): Add LIBX11 as an input.

Merge branch 'python'

gnu: gnutls: Upgrade to 3.2.4.

* gnu/packages/gnutls.scm (gnutls): Update to 3.2.4; remove 'arguments'
  field, remove "patch/fix-tests" from the inputs.
* gnu/packages/patches/gnutls-fix-tests-on-32-bits-system.patch: Remove.
* gnu-system.am (dist_patch_DATA): Adjust accordingly.

gnu: Add python2-mechanize.

* gnu/packages/python.scm (python2-mechanize): New variable.

gnu: Add python2-sqlite.

* gnu/packages/python.scm (python2-sqlite): New variable.

gnu: avahi, dbus: Use /var as $localstatedir.

* gnu/packages/avahi.scm (avahi): Pass '--localstatedir'; add
  'patch/localstatedir'.
* gnu/packages/glib.scm (dbus): Pass '--localstatedir' and
  '--with-session-socket-dir'; add 'patch/localstatedir'.
* gnu/packages/patches/avahi-localstatedir.patch,
  gnu/packages/patches/dbus-localstatedir.patch: New files.
* gnu-system.am (dist_patch_DATA): Add them.

gnu: Update python-babel, python2-babel to 1.3.

* gnu/packages/python.scm (python-babel, python2-babel): Update to 1.3.

gnu: Move helper code to (gnu system …) modules.

* gnu/packages/grub.scm (<menu-entry>, grub-configuration-file): Move
  to...
* gnu/system/grub.scm: ... here.  New file.
* gnu/packages/linux.scm (<pam-service>, <pam-entry>,
  pam-service->configuration, pam-service->directory,
  %pam-other-services, unix-pam-service): Move to...
* gnu/system/linux.scm: ... here.  New file.
* gnu/system/vm.scm (passwd-file): Move to...
* gnu/system/shadow.scm: ... here.  New file.
* gnu-system.am (GNU_SYSTEM_MODULES): Add
  gnu/system/{grub,linux,shadow}.scm.

gnu: vm: Remove potluck hacks.

* gnu/system/vm.scm (example1): Remove.
  (example2): Rename to...
  (system-qemu-image): ... this.  Add 'store' parameter, and remove call
  to 'open-connection'.

gnu: Add python-dateutil, python2-dateutil.

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

guix: python: Create module installation path and add it to PYTHONPATH during
  the installation phase.

* guix/build/python-build-system.scm (get-python-version): New procedure.
* guix/build/python-build-system.scm (install): Create and add path.
* gnu/packages/python.scm (python-setuptools): Drop path creation code.

gnu: vm: Setup PAM.

* gnu/system/vm.scm (example2): Use 'pam-services->directory'.  Change
  POPULATE to create /etc/pam.d, /etc/login.defs, and /var/run.  Change
  BOOT to spawn syslogd; boot to Bash.  Add inputs.

gnu: vm: Create shadow files with the right format.

* gnu/system/vm.scm (passwd-file): When SHADOW? is true, use the right
  shadow(5) format.  Always add a trailing newline.