Log Message:
Update to gnats 4.1.0.
Make a overhaul of the package and bring it closer to pkgsrc standards.
Addresses PR 26174 by Hauke Fath.

changes:

This is GNATS 4.1.0, a release that incorporates multiple bug fixes
and enhancements that have been committed to CVS since the release of
GNATS 4.0.  Notable enhancements include:

- Upgrade to autoconf 2.59 generated configure scripts.
- New PR numbers are reported to the client upon new submissions
- Rewrite of install-sid.  Now, rather than editing send-pr, which can
  be installed on a read-only partition, install-sid creates or edits
  user or site configuration files ~/.send-pr.conf or
  /etc/gnats/send-pr.conf.
- Removal of libiberty, old manpages, and old build framework cruft
- Performance enhancements to indexing code
- Various cleanups and bugfixes.  See the ChangeLog files for details.