Avoid weak-vtables warnings
Fix Doxygen comments
Remove unnecessary includes
Fix conversion warnings
Fix shadowing warnings
Use `safe_equal` in == operator of `optional`
Fix unused argument warning
Explicitly provide `operator=` for `unit_t`
Pass correct type for `super` in `local_actor`
Use correct C++ casts
Fix shadowing warning
Fix parameter name in Doxygen comment
Fix shadowing warning
Fix "undefined macro" warnings
Fix flags for --more-clang-warnings