guix package: Use 'profile-generations'.

* guix/scripts/package.scm (guix-package)[process-actions]: Use
  'profile-generations' instead of the equivalent code.

profiles: Add 'profile-generations'.

* guix/profiles.scm (profile-generations): New procedure.

system: Add support for boot-time mapped devices.

* gnu/build/linux-boot.scm (boot-system): Add #:pre-mount parameter and
  honor it.
* gnu/system/linux-initrd.scm (base-initrd): Add #:mapped-devices
  parameter.  Add 'device-mapping-commands' variable, and use it to
  build the #:pre-mount argument of 'boot-system'.
* gnu/system.scm (mapped-device-user,
  operating-system-user-mapped-devices,
  operating-system-boot-mapped-devices): New procedures.
  (device-mapping-services): Use 'operating-system-user-mapped-devices'
  instead of 'operating-system-mapped-devices'.
  (operating-system-initrd-file): Call the initrd with #:mapped-devices.

activation: Ensure existing user accounts have the right settings.

* gnu/build/activation.scm (modify-user, ensure-user): New procedures.
  (activate-users+groups): Systematically call 'ensure-user'.

gnu: valgrind: Update to 3.10.0.

* gnu/packages/valgrind.scm (valgrind): Update to 3.10.0.
* gnu/packages/patches/valgrind-glibc.patch: Remove.
* gnu-system.am (dist_patch_DATA): Adjust accordingly.

gnu: duplicity: Add dependency on util-linux.

* gnu/packages/backup.scm (duplicity)[native-inputs]: Add util-linux.

gnu: ots: Build sequentially.

* gnu/packages/ots.scm (ots)[arguments]: New field.

gnu: Add sound-theme-freedesktop.

Suggested by Federico Beffa <beffa@ieee.org>.

* gnu/packages/libcanberra.scm (sound-theme-freedesktop): New variable.

gnu: libcanberra: Add dependency on PulseAudio and eudev.

* gnu/packages/libcanberra.scm (libcanberra): Add PulseAudio and eudev
  as inputs.

gnu: emacs: Switch to GTK+ 3.

Suggested by Federico Beffa <beffa@ieee.org>.

* gnu/packages/emacs.scm (emacs): Switch to GTK+ 3.

offload: Use a total order when sorting available machines.

* guix/scripts/offload.scm (machine-less-loaded?, machine-faster?):
  Remove.
  (machine-power-factor): New procedure.
  (machine-less-loaded-or-faster?): Use it.

offload: Try another machine when the "best" machine is overloaded.

* guix/scripts/offload.scm (choose-build-machine): When BEST is
  overloaded, try the other machines.

linux-boot: Ask fsck for a progress bar.

* gnu/build/file-systems.scm (check-file-system): Pass '-C 0' to FSCK.
  Suggested by Mark H. Weaver.

gnu: guile-charting: Update to 0.2.0.

* gnu/packages/guile.scm (guile-charting): Update to 0.2.0.  Remove
  now-unnecessary cruft from 'snippet'.  Modify 'godir' in Makefile.in.

system: Fix value of 'EUDEV_RULES_DIRECTORY'.

* gnu/services/base.scm (udev-service): Append "/lib/udev/rules.d" to
  EUDEV_RULES_DIRECTORY.

gnu: Fix typos.

* gnu/packages/cdrom.scm (cdparanoia): Double space in description.
* gnu/packages/maths.scm (hdf5): Double space in synopsis.

gnu: linux-libre: Update to 3.16.3.

* gnu/packages/linux.scm (linux-libre): Update to version 3.16.3.

system: Add udev rule for /dev/kvm.

* gnu/services/base.scm (kvm-udev-rule): New procedure.
  (udev-service): Use it, and add it to RULES.
  (guix-build-accounts): Add "kvm" to the 'supplementary-groups' field.
* gnu/system/shadow.scm (%base-groups): Add "kvm".

linux-initrd: Remove now obsolete #:guile-modules-in-chroot? parameter.

* gnu/build/linux-boot.scm (boot-system): Remove
  #:guile-modules-in-chroot? and related code.
* gnu/system/linux-initrd.scm (base-initrd): Likewise.
* gnu/system/vm.scm (expression->derivation-in-linux-vm): Remove
  #:guile-modules-in-chroot? argument in 'base-initrd' call.

doc: Remove a couple of limitations.

* doc/guix.texi (System Installation): Remove encrypted disks and swap
  from the limitations.