Changes

* Some experimentations and customizations, with these GNU gettext utilities for gramps' translation strings, were tested with success some years ago. You can still get an overview via an ancien [https://raw.githubusercontent.com/gramps-project/addons-source/refs/heads/maintenance/gramps51/lxml/setup.py 'setup.py' stand-alone script for an addon (5.1 branch)] or the [https://raw.githubusercontent.com/gramps-project/addons-source/refs/heads/maintenance/gramps60/setup.py setup one at the top of the addons-sources repository].