Bug#850301: xorg: Move from asciidoc to asciidoc-base as dependency

[Joseph Herlant <herlantj@gmail.com>]

Package: Xorg
Severity: wishlist

Dear Maintainer,

Asciidoc has been split in different packages in #637006 and #729242.
This split has arrived in Testing.

To lower the number of dependencies to install during the build, could
you evaluate the switch of the build-depends from asciidoc to
asciidoc-base instead of asciidoc please?

asciidoc-base is enough to build manpages and html pages.

In addition to that, the xmlto package has been added to the
recommends of the asciidoc-base package in #692274, so it might not be
mandatory to have it in the buid-depends anymore.

Thanks for your help,
Joseph