include minetest-mapper into the minetest-data package
move the install override stuff from target override_dh_auto_build to override_dh_install
don't install in-package fonts, but use system-wide ones
Actually install the upstream changelog

Also, don't install them directly in /usr/share/doc but in
/usr/share/doc/$pkg
add a little debian/TODO file with the two points we still have to do
upload to unstable