- Add screwdriver to optional_depends
- Fix luacheck warnings (mostly removing unused/legacy stuff)
Note: sm_light used to be a light_source value for lattice small lantern,
but when this was changed, only half of the lines were deleted
(including the declaration). The other half has been preserved because
it was part of an if-arm that "seems" unrelated (but it only seems).
- Improve french translation
