Rather than having to manually build the locale aware man paths with
`install_data('foo.fr.1', install_dir: join_paths(get_option('mandir'), 'fr', 'man1'), rename: 'foo.1')`
Support doing
`install_man('foo.fr.1', locale: 'fr')`
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082
Remove the code responsible for implicitly compressing manpages as .gz
files. It has been established that manpage compression is a distro
packager's task, with existing distros already having their own
implementations of compression.
Fixes#4330