gnu: mupdf: Unbundle mujs.

* gnu/packages/pdf.scm (mupdf)[source]: Remove bundled mujs.
[inputs]: Add mujs.

gnu: Add mujs.

* gnu/packages/javascript.scm (mujs): New variable.

gnu: mupdf: Use https.

* gnu/packages/pdf.scm (mupdf)[source]: Use https.
[home-page]: Same.

gnu: pdf.scm: Arrange modules alphabetically.

* gnu/packages/pdf.scm: Arrange modules alphabetically.

gnu: lash: Don't build static libraries.

* gnu/packages/audio.scm (lash)[arguments]: Add configure-flag to
disable static libraries.

gnu: lash: Don't build lashd.

This fixes bug#28174.

* gnu/packages/audio.scm (lash)[arguments]: Add phase to skip building lashd.

gnu: glib-networking: Update to 2.54.1.

* gnu/packages/gnome.scm (glib-networking): Update to 2.54.1.

gnu: ffmpeg: Reduce the size of the closure.

* gnu/packages/video.scm (ffmpeg)[arguments]: Add new configure flags to
disable the html man pages and the static libraries.

gnu: mupdf: Use Texinfo for the description.

* gnu/packages/pdf.scm (mupdf)[description]: Use Texinfo to mark up the
description.

gnu: w3m: Find an editor in the environment.

* gnu/packages/w3m.scm (w3m)[arguments]: Pass an empty value for --with-editor
in #:configure-flags.
[source]: Use git-file-name.

gnu: mupdf: Actually fix CVE-2017-15587.

The original fix could be removed by an optimizing compiler.

* gnu/packages/patches/mupdf-CVE-2017-15587.patch: Revise patch.

gnu: libusb-compat: Use the same home page as libusb.

* gnu/packages/libusb.scm (libusb-compat)[home-page]: Update.

gnu: fcgi: Fix typo in description.

* gnu/packages/web.scm (fcgi)[description]: Fix typo.

gnu: fcgi: Use archived home page fork.

* gnu/packages/web.scm (fcgi)[home-page]: Use archived version.

gnu: lynx: Use new home page.

* gnu/packages/web-browsers.scm (lynx)[home-page]: Update.

gnu: perl-mime-types: Update to 2.14.

* gnu/packages/perl.scm (perl-mime-types): Update to 2.14.

gnu: mailutils: Update to 3.4.

* gnu/packages/mail.scm (mailutils): Update to 3.4.

gnu: emacs-emms: Update to 4.4.

* gnu/packages/emacs.scm (emms): Update to 4.4.

gnu: nyacc: Update to 0.82.4.

* gnu/packages/mes.scm (nyacc): Update to 0.82.4.

git: Check whether 'clone-init-options' is defined.

This is a followup to 195f0d05c3f64e17e84b2683a7045a14ec578d61.

* guix/git.scm (clone*): Check whether 'clone-init-options' is defined
before using it.