* mdate.pl: Report dates in ISO 8601 format (for man page center
footers). That is what we prescribe in groff_man_style(7), so it's
only fair that we dog food our own recommendation.
* update-copyright.sh: use gnulib's 'update-copyright' script. Pass
this script in directories 'arch', 'contrib', 'font', 'man', 'tmac',
'src' and on a list of extra files.
* FOR-RELEASE: mention this point.
Use gnulib's update-copyright script.
* src/roff/groff/groff.cpp: update the printf displayed when 'groff -v' is invoked.
* FOR-RELEASE: mention this point.
groff already requires perl to build. This version is much shorter
and easier to understand than the shell/awk version: we don't have
to worry about convincing ls to produce output that we can parse,
and we don't have to play games with the way that the same field may
contain either the year or the time depending on how old the file
is.
While I'm at it, this version also adds `SOURCE_DATE_EPOCH' support
for reproducible builds: when `SOURCE_DATE_EPOCH' is set, files are
considered to have been last modified at that time.
* mdate.sh: Rewrite in Perl, moving to ...
* mdate.pl: ... this new file.
* Makefile.am (EXTRA_DIST, .man): Update references.
