Log Message:
textproc/ruby-asciidoctor: update to 2.0.16.

Summary

This is a patch release with a big impact, bringing with it several
notable changes. First, two regressions have been fixed when using
negated wildcards in include tag filtering, and the meaning of negated
wildcards in tag filtering has been clarified in general. Second, the
source of the default stylesheet has been imported into this repository
(now managed using a PostCSS build with autoprefixer and cssnano).
Third, an internal change was made to how lines are iterated by the
reader (switching from a stack to a queue), which will substantially
improve the performance of Asciidoctor.js when processing large files.
Finally, numerous improvements were made to the man page converter.

This release also includes a handful of smaller bug fixes, including two
scenarios where an undefined method error was creeping in. Several
impactful updates were made to the documentation during this release
cycle as well, most notably on the topic of generating man pages. An
initial set of changes have been applied to the code base in preparation
for enabling RuboCop to enforce a code style. The remainder of those
changes, as well as the task itself, have already been applied to the
default branch. Those updates will also be applied to the branch for
this release line following this release. Speaking of release
lines, the default branch is now open for 2.1.x development and beyond!

Consult the CHANGELOG to find the full list of changes in this release.