build: Fix manpage generation at dist time
The AsciiDoc API only exposes the capabilities of asciidoc, but not the related a2x tool. Fix generating the manpages by shelling out to the command line tool instead.
Fixes #4320 (closed)
The AsciiDoc API only exposes the capabilities of asciidoc, but not the related a2x tool. Fix generating the manpages by shelling out to the command line tool instead.
Fixes #4320 (closed)