gnu: xmlto: Update to 0.0.28.

* gnu/packages/xml.scm (xmlto): Update to 0.0.28.

gnu: vapoursynth: Update to 28.

* gnu/packages/video.scm (vapoursynth): Update to 28.

gnu: python2-scikit-image: Use custom 'python2-' packages.

* gnu/packages/python.scm (python2-scikit-image): Use customized 'python2-'
  versions of 'matplotlib', 'numpy' and 'scipy'.

gnu: python2-pandas: Use custom 'python2-numpy'.

* gnu/packages/python.scm (python2-pandas): Do it.

gnu: python2-ipython: Use custom 'python2-numpy'.

* gnu/packages/python.scm (python2-ipython): Do it.

gnu: ffmpeg: Update to 2.8.3 [fixes CVE-2015-{8216,8217,8218,8219}].

* gnu/packages/video.scm (ffmpeg): Update to 2.8.3.

gnu: freeipmpi: Update to 1.5.1.

* gnu/packages/freeipmi.scm (freeipmi): Update to 1.5.1.

daemon: Add 'buildMode' parameter to 'buildPaths' RPC.

* nix/libstore/worker-protocol.hh (PROTOCOL_VERSION): Bump to 0x10f.
* nix/libstore/remote-store.cc (RemoteStore::buildPaths): Send the
BUILDMODE when the daemon supports it.  Reject invalid values of
BUILDMODE for old daemons.
* nix/nix-daemon/nix-daemon.cc (performOp) <wopBuildPaths>: Read the
build mode when the client supports it.

daemon: optimizePath: Detect some .links corruptions.

If automatic store optimisation is enabled, and a hard-linked file in
the store gets corrupted, then the corresponding .links entry will
also be corrupted. In that case, trying to repair with --repair or
--repair-path won't work, because the new "good" file will be replaced
by a hard link to the corrupted file. We can catch most of these cases
by doing a sanity-check on the file sizes.

daemon: Fix namespace issue.

daemon: Support SHA-512 hashes.

Fixes #679.

Note: on x86_64, SHA-512 is considerably faster than SHA-256 (198 MB/s
versus 131 MB/s).

Co-authored-by: Ludovic Courtès <ludo@gnu.org>

daemon: int2String -> std::to_string.

daemon: Filter build-chroot-dirs entries that conflict with derivation outputs.

Fixes https://github.com/NixOS/nixpkgs/issues/9504.

Note that this means we may have a non-functional /bin/sh in the
chroot while rebuilding Bash or one of its dependencies. Ideally those
packages don't rely on /bin/sh though.

daemon: Prevent .chroot from being GC'ed when using LocalStore::buildDerivation()

Fixes #616.

gnu: python-matplotlib: Adjust path to figures in 'info' file.

* gnu/packages/python.scm (python-matplotlib): Do it.

gnu: python-ipython: Don't use the bootstrap version of 'python-numpy'.

* gnu/packages/python.scm (python-ipython): Do it.

gnu: python-matplotlib: Add 'TkAgg' backend and update to version '1.4.3'.

* gnu/packages/python.scm (python-matplotlib, python2-matplotlib): Do it.
* gnu/packages/patches/matplotlib-setupext-tk.patch: New file.
* gnu-system.am (dist_patch_DATA): Add the new patch.

gnu: opus: Update to 1.1.1.

* gnu/packages/xiph.scm (opus): Update to 1.1.1.

gnu: libbluray: Update to 0.9.2.

* gnu/packages/video.scm (libbluray): Update to 0.9.2.

import: pypi: Updater silently ignores packages without source.

Reported by Andreas Enge <andreas@enge.fr>
at <https://lists.gnu.org/archive/html/guix-devel/2015-11/msg00764.html>.

* guix/import/pypi.scm (&missing-source-error): New error type.
(latest-source-release): Raise it instead of using 'error'.
(pypi->guix-package): Guard against it and use 'leave' to report the
error.
(latest-release): Guard against it and return #f when caught.