gnu: gnuplot: Update to 5.0.2.

* gnu/packages/maths.scm (gnuplot): Update to 5.0.2.

gnu: lablgtk: Build cmxa libraries.

* gnu/packages/ocaml.scm (lablgtk)[arguments]: Add the make target "opt"
  to also build *.cmxa files.

gnu: ocaml: Set search path.

* gnu/packages/ocaml.scm (ocaml): Register OCAMLPATH as a search path.

gnu: Add ocaml-findlib.

* gnu/packages/ocaml.scm (ocaml-findlib): New variable.
* gnu/packages/patches/ocaml-findlib-make-install.patch: New file.
* gnu-system.am (dist_patch_DATA): Register it.

gnu: gnupg: Add upstream fix for test failures on x86_64.

Fixes <https://debbugs.gnu.org/22558>.

* gnu/packages/patches/gnupg-simple-query-ignore-status-messages.patch: New
  file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/gnupg.scm (gnupg)[source]: Add patch.

gnu: Add tclxml.

* gnu/packages/patches/tclxml-3.2-install.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/tcl.scm (tclxml): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: Split acme into python-acme and python2-acme.

* gnu/packages/tls.scm (acme): Split variable into...
(python-acme, python2-acme): ...both Python variants.
(letsencrypt)[propagated-inputs]: Update user of renamed variable.

gnu: python-wheel: Define 'python2-variant'.

* gnu/packages/python.scm (python-wheel)[properties]: New field.
(python2-wheel): Use 'strip-python2-variant'.
(python2-requests): Take the result of 'package-with-python2' directly.
* gnu/packages/openstack.scm (python2-requests-mock): Likewise.
(python2-oslosphinx): Likewise.

gnu: python-jsonschema: Define 'python2-variant'.

* gnu/packages/python.scm (python-jsonschema)[properties]: New field.
(python2-jsonschema): Use 'strip-python2-variant'.
* gnu/packages/openstack.scm (python2-tempest-lib): Take the result of
'package-with-python2' directly.

gnu: python-cryptography: Define 'python2-variant'.

* gnu/packages/python.scm (python-cryptography)[properties]: New field.
(python2-cryptography): Use 'strip-python2-variant'.
(python2-pyopenssl): Take the result of 'package-with-python2' directly.

gnu: Add tcllib.

* gnu/packages/tcl.scm (tcllib): New variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: tcl: Use tcl/tk license.

* gnu/packages/tcl.scm (tcl)[license]: Use the tcl/tk license variable.

Signed-off-by: Leo Famulari <leo@famulari.name>

gnu: macs: Update to 2.1.0.20151222.

* gnu/packages/bioinformatics.scm (macs): Update to 2.1.0.20151222.

gnu: macs: Use "pypi-uri".

* gnu/packages/bioinformatics.scm (macs)[source]: Use "pypi-uri" to
  build source URI.

gnu: python2-fastlmm: Update to 0.2.21.

* gnu/packages/python.scm (python2-fastlmm): Update to 0.2.21.

gnu: python2-pysnptools: Update to 0.3.5.

* gnu/packages/python.scm (python2-pysnptools): Update to 0.3.5.

gnu: python-numpy-bootstrap: Update to 1.10.4.

* gnu/packages/python.scm (python-numpy-bootstrap): Update to 1.10.4.

gnu: python-pandas: Update to 0.16.2.

* gnu/packages/python.scm (python-pandas): Update to 0.16.2.

gnu: Add gnunet-gtk.

* gnu/packages/gnunet.scm (gnunet-gtk): New variable.

Co-authored-by: Ricardo Wurmus <rekado@elephly.net>

gnu: gnunet: Add gstreamer and plugins to inputs.

* gnu/packages/gnunet.scm (gnunet)[inputs]: Add "gstreamer" and
  "gst-plugins-base".