gnu: youtube-dl: Update to 2017.02.16.

* gnu/packages/video.scm (youtube-dl): Update to 2017.02.16.

gnu: Add ocaml-ppx-compare.

* gnu/packages/ocaml.scm (ocaml-ppx-compare): New variable.

gnu: Add ocaml-ppx-bench.

* gnu/packages/ocaml.scm (ocaml-ppx-bench): New variable.

gnu: Add ocaml-ppx-inline-test.

* gnu/packages/ocaml.scm (ocaml-ppx-inline-test): New variable.

gnu: Add ocaml-ppx-type-conv.

* gnu/packages/ocaml.scm (ocaml-ppx-type-conv): New variable.

gnu: Add ocaml-ppx-deriving.

* gnu/packages/ocaml.scm (ocaml-ppx-deriving): New variable.

gnu: Add ocaml-cppo.

* gnu/packages/ocaml.scm (ocaml-cppo): New variable.

gnu: Add ocaml-ppx-driver.

* gnu/packages/ocaml.scm (ocaml-ppx-driver): New variable.

gnu: Add ocaml-ppx-optcomp.

* gnu/packages/ocaml.scm (ocaml-ppx-optcomp): New variable.

gnu: Add ocaml-ppx-core.

* gnu/packages/ocaml.scm (ocaml-ppx-core): New variable.

gnu: Add ocaml-fieldslib.

* gnu/packages/ocaml.scm (ocaml-fieldslib): New variable.

gnu: gptfdisk: Install the documentation.

* gnu/packages/disk.scm (gptfdisk)[arguments]: Install the manpages.

gnu: python-icalendar: Update to 3.11.3.

* gnu/packages/python.scm (python-icalendar): Update to 3.11.3.

gnu: Add qutebrowser.

* gnu/packages/web.scm (qutebrowser): New variable.

gnu: python-pyqt: Propagate python-sip.

* gnu/packages/qt.scm (python-pyqt)[propagated-inputs]: New field.

gnu: Add python-pypeg2.

* gnu/packages/python.scm (python-pypeg2): New variable.

gnu: Add python-cssutils.

* gnu/packages/python.scm (python-cssutils): New variable.
(python2-cssutils)[native-inputs]: Remove unused python2-mock.

gnu: gparted: Update to 0.28.0.

* gnu/packages/disk.scm (gparted): Update to 0.28.0.

gnu: Add guildhall.

* gnu/packages/guile.scm (guildhall): New variable.

hydra: Add "aarch64-linux-gnu" as a cross-compilation target.

* build-aux/hydra/gnu-system.scm (%cross-targets): Add
"aarch64-linux-gnu".