docbook-xsl-1.79.2-1.18

- Abandom the docbook-xsl-stylesheets-script package.
  The dbtoepub script is available from the rubygem-dbtoepub
  package.
  The script pdf2index is available in docbook-xsl-pdf2index

- First attempt to build the two DocBook stylesheet packages
  from a single source:
  - Added xslnons-build script from upstream.
  - Improved dbxslt-install.sh script a lot

- Fix bsc#1063066:
  From 1.79.1 and later, upstream decided to release namespace
  aware stylesheets only. The non-NS stylesheets have to be built
  with the "xslnons-build" script (taken from upstream).
  This is integrated now.
  The switch from NS-aware to non-NS stylesheets help to fix this
  problem.

- Restore working patch (bsc#1063066):
  * Rebase docbook-xsl-stylesheets-non-recursive_string_subst.patch

- Update to version 1.79.2
- Rebase docbook-xsl-stylesheets-non-recursive_string_subst.patch
- callout-gen is removed

- Add docbook-xsl-stylesheets-non-recursive_string_subst.patch
  Use str:replace from exslt.org to implement string.subst
  string.subst implementation causes recursion issues when building
  systemd documentation. This issue has been reported in
  https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=765567 and
  https://bugs.archlinux.org/task/54694 .
  Taken from https://github.com/fishilico/xslt10-stylesheets/commit/a7df4fbbef3ab0f97d50aa47f2ccfa0630a2686e

- Explicitly package %{_docdir}/%{name} to fix build with RPM 4.13.

- Use update-xml-catalog

- Update download urls

- Update to version 1.79.0, see
  http://snapshots.docbook.org/xsl/RELEASE-NOTES.html#V1.79.0
  for details (Mostly bugfix release)
- Remove obsolete patches
  * docbook-xsl-stylesheets-epub3-base.dir.patch
  * docbook-xsl-stylesheets-manpages-other-r9847.patch
- Perform a spec-cleaner on the spec file