gnu: Use PACKAGE/INHERIT in more places.

gnu: Use PACKAGE/INHERIT in more places.

* gnu/packages/algebra.scm (fftwf, fftw-openmpi),
gnu/packages/audio.scm (ztoolkit-rsvg),
gnu/packages/bioinformatics.scm (python2-dendropy),
gnu/packages/boost.scm (boost-with-python2),
gnu/packages/check.scm (python2-mock, python2-pytest-mock),
gnu/packages/cups.scm (hplip-minimal),
gnu/packages/freedesktop.scm (libinput-minimal),
gnu/packages/gettext.scm (gnu-gettext),
gnu/packages/glib.scm (python2-pygobject),
gnu/packages/gnome.scm (gdl-minimal, libsoup-minimal, python2-pyatspi),
gnu/packages/groff.scm (groff-minimal),
gnu/packages/jami.scm (ffmpeg-jami),
gnu/packages/libcanberra.scm (libcanberra/gtk+-2),
gnu/packages/lirc.scm (python2-lirc),
gnu/packages/llvm.scm (clang-runtime-3.5),
gnu/packages/mpi.scm (java-openmpi, openmpi-thread-multiple),
gnu/packages/node.scm (libnode),
gnu/packages/onc-rpc.scm (libtirpc/hurd),
gnu/packages/python-compression.scm (bitshuffle-for-snappy),
gnu/packages/python-crypto.scm (python2-pycrypto, python2-cryptography)
(python2-cryptography, python2-m2crypto),
gnu/packages/python-web.scm (python2-html2text, python2-tornado)
(python2-terminado, python2-ndg-httpsclient, python2-websocket-client)
(python2-rauth, python2-url, python2-s3transfer),
gnu/packages/python-xyz.scm (python2-psutil, python2-serpent)
(python2-humanfriendly, python2-empy, python2-parse-type, python2-polib)
(python2-jsonschema, python2-pystache, python2-cython, python2-numpydoc)
(python2-ipyparallel, python2-traitlets, python2-dbus)
(python2-beautifulsoup4, python2-pep517, python2-flake8, python2-llfuse)
(python2-tlsh, python-file, python2-notebook, python-jupyter-console-minimal)
(python2-contextlib2, python2-promise, python2-anyjson, python2-amqp)
(python2-kombu, python2-billiard, python2-celery, python2-whoosh)
(python2-jellyfish, python-rope, ptpython-2, python2-binaryornot)
(python2-setproctitle, python2-argcomplete, python2-xopen, python2-isort)
(python2-radon, python2-rfc6555, python2-activepapers, python2-send2trash)
(python2-cloudpickle, python2-reparser),
gnu/packages/python.scm (python2-called-python),
gnu/packages/qt.scm (python2-sip, python-pyqt-without-qtwebkit, python2-pyqt)
(python-qscintilla, python-pyqt+qscintilla),
gnu/packages/scanner.scm (sane-backends),
gnu/packages/sdl.scm (guile3.0-sdl2),
gnu/packages/selinux.scm (checkpolicy, libselinux, libsemanage, secilc)
(python-sepolgen, policycoreutils),
gnu/packages/serialization.scm (lua5.1-libmpack, lua5.2-libmpack),
gnu/packages/simulation.scm (fenics),
gnu/packages/statistics.scm (python2-statsmodels),
gnu/packages/texinfo.scm (info-reader),
gnu/packages/wxwidgets.scm (wxwidgets-gtk2, wxwidgets-gtk2-3.1),
gnu/packages/xml.scm (xmlsec-nss),
gnu/packages/xorg.scm (uim-gtk, uim-qt),
guix/build-system/python.scm (package-with-explicit-python)
(strip-python2-variant): Use PACKAGE/INHERIT.