gnu: cracklib: Fix buffer overflow.

* gnu/packages/patches/cracklib-fix-buffer-overflow.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/password-utils.scm (cracklib)[source]: Use it.

gnu: libtiff: Fix CVE-2016-{10092,10093,10094} and others.

* gnu/packages/patches/libtiff-CVE-2016-10092.patch,
gnu/packages/patches/libtiff-CVE-2016-10093.patch,
gnu/packages/patches/libtiff-CVE-2016-10094.patch,
gnu/packages/patches/libtiff-assertion-failure.patch,
gnu/packages/patches/libtiff-divide-by-zero-ojpeg.patch,
gnu/packages/patches/libtiff-divide-by-zero-tiffcp.patch,
gnu/packages/patches/libtiff-divide-by-zero-tiffcrop.patch,
gnu/packages/patches/libtiff-divide-by-zero.patch,
gnu/packages/patches/libtiff-heap-overflow-pixarlog-luv.patch,
gnu/packages/patches/libtiff-heap-overflow-tif-dirread.patch,
gnu/packages/patches/libtiff-heap-overflow-tiffcp.patch,
gnu/packages/patches/libtiff-heap-overflow-tiffcrop.patch,
gnu/packages/patches/libtiff-invalid-read.patch,
gnu/packages/patches/libtiff-null-dereference.patch,
gnu/packages/patches/libtiff-tiffcp-underflow.patch: New files.
* gnu/local.mk (dist_patch_DATA): Add them.
* gnu/packages/image.scm (libtiff)[replacement]: New field.
(libtiff/fixed): New variable.

gnu: notmuch: Update to 0.23.5.

* gnu/packages/mail.scm (notmuch, python2-notmuch): Update to 0.23.5.

gnu: xapian: Update to 1.4.2.

* gnu/packages/search.scm (xapian): Update to 1.4.2.

gnu: gnutls: Replace with 3.5.8 [fixes GNUTLS-SA-2017-{1,2}].

* gnu/packages/tls.scm (gnutls-3.5.8): New variable.
(gnutls)[replacement]: New field.

gnu: rofi: Update to 1.3.1.

* gnu/packages/xdisorg.scm (rofi): Update to 1.3.1.

gnu: youtube-dl: Update to 2017.01.10.

* gnu/packages/video.scm (youtube-dl): Update to 2017.01.10.  Change
URLs to yt-dl.org.

gnu: e2fsprogs: Remove timestamp from 'libext2fs.info.gz'.

* gnu/packages/linux.scm (e2fsprogs)[source](snippet): Patch
'doc/Makefile.in' to use the '-n' option of gzip.

gnu: e2fsprogs: Use symlinks instead of hard links.

* gnu/packages/linux.scm (e2fsprogs)[arguments]: Pass
"--enable-symlink-install".

gnu: Add sysstat.

* gnu/packages/linux.scm (sysstat): New variable.

gnu: python-click: Update to 6.7.

* gnu/packages/python.scm (python-click): Update to 6.7.

gnu: linux-libre@4.4: Update hash for fixed upstream tarball.

The initial upload of linux-libre-4.4.41-gnu.tar.xz was corrupted.

* gnu/packages/linux.scm (linux-libre-4.4)[source]: Update hash.

gnu: libgit2, python-pygit2: Update to 0.25.1 [security fixes].

See <http://www.openwall.com/lists/oss-security/2017/01/10/5>.

* gnu/packages/version-control.scm (libgit2): Update to 0.25.1.
* gnu/packages/python.scm (python-pygit2): Update to 0.25.0.

gnu: Add btrfs-progs/static.

* gnu/packages/linux.scm (btrfs-progs/static): New variable.

gnu: e2fsck/static: Only copy e2fsck.

* gnu/packages/linux.scm (e2fsck/static)[arguments]: Only copy e2fsck.
  [synopsis, description]: Adjust accordingly.

gnu: Add pcc.

* gnu/packages/c.scm (pcc): New variable.

gnu: ruby-sqlite3: Update to 1.3.13.

* gnu/packages/ruby.scm (ruby-sqlite3): Update to 1.3.13.

gnu: linux-libre: Update to 4.9.2.

* gnu/packages/linux.scm (%linux-libre-version, %linux-libre-hash)
(linux-libre): Update to 4.9.2.

gnu: linux-libre@4.4: Update to 4.4.41.

* gnu/packages/linux.scm (linux-libre-4.4): Update to 4.4.41.

gnu: emacs-guix: Update to 0.2.2.

* gnu/packages/emacs.scm (emacs-guix): Update to 0.2.2.