Solution for Debian/Ubuntu: install a trigger to restart mysqld
automatically whenever a package changes something in /etc/mysql
or in /etc/systemd/system/mariadb.service.d
These changes update the contents and behaviour of current packages
to match the current packaging in Debian official repos.
Keep mtr test scope small.
Updating maintainer scripts also required regenerating the translations.
Rules based on modern dh_* buildtools.
Update control file with new Debian conventions:
- Provide virtual-mysql-* virtual packages
- Recommends perl modules instead of Depends
