Remove old defaults system
Introduce priority-based fallback list
Use new functions for map_meta special functions
Change groups to use end tags
Unittest changes:
* Adapt unittest to the new code
* Compare Settings objects
Unified flags handling in C++ and Lua Settings API
-> Reading only, for now. Writing can be implemented later, if needed.
API function to read the currently active flags
-> was impossible from Lua
Co-authored-by: Wuzzy <wuzzy2@mail.ru>
* Fix many issues reported by clang-tidy
We have many issues in code related to some performance to float <-> double.
Clang-tidy reported it in performance-type-promotion-in-math-fn
I fixed many of them. It's not ready for a promote to blocking
Also fix some value which should be const-ref
