Adds `header_guards.sh` bash script, used in CI to validate future changes. Can be run locally to fix invalid header guards.
Happy new year to the wonderful Godot community!
* Add support for decimal numeric entities to String::xml_unescape * Add more error checks to String::xml_unescape * Refactor XMLParser to use String::xml_unescape instead of an internal implementation
Rémi Verschelde
Henry Conklin