This adds a way to ensure that methods that were modified in the Godot API will continue working in older builds of GDExtension even if the new signature is different.
```C++
// New version (changed)
ClassDB::bind_method(D_METHOD("add_sphere","radius","position"),&MyShapes::add_sphere);
// Compatibility version (still available to extensions).
ClassDB::bind_compatibility_method(D_METHOD("add_sphere","radius"),&MyShapes::_compat_add_sphere);
```
**Q**: If I add an extra argument and provide a default value (hence can still be called the same), do I still have to provide the compatibility version?
**A**: Yes, you must still provide a compatibility method. Most language bindings use the raw method pointer to do the call and process the default parameters in the binding language, hence if the actual method signature changes it will no longer work.
**Q**: If I removed a method, can I still bind a compatibility version even though the main method no longer exists?
**A**: Yes, for methods that were removed or renamed, compatibility versions can still be provided.
**Q**: Would it be possible to automate checking that methods were removed by mistake?
**A**: Yes, as part of a future PR, the idea is to add a a command line option to Godot that can be run like : `$ godot --test-api-compatibility older_api_dump.json`, which will also be integrated to the CI runs.
As many open source projects have started doing it, we're removing the
current year from the copyright notice, so that we don't need to bump
it every year.
It seems like only the first year of publication is technically
relevant for copyright notices, and even that seems to be something
that many companies stopped listing altogether (in a version controlled
codebase, the commits are a much better source of date of publication
than a hardcoded copyright statement).
We also now list Godot Engine contributors first as we're collectively
the current maintainers of the project, and we clarify that the
"exclusive" copyright of the co-founders covers the timespan before
opensourcing (their further contributions are included as part of Godot
Engine contributors).
Also fixed "cf." Frenchism - it's meant as "refer to / see".
Non-exhaustive list of case-sensitive renames:
GDExtension -> GDNative
GDNATIVE -> GDEXTENSION
gdextension -> gdnative
ExtensionExtension ->Extension (for where there was GDNativeExtension)
EXTENSION_EXTENSION ->EXTENSION (for where there was GDNATIVE_EXTENSION)
gdnlib -> gdextension
gdn_interface -> gde_interface
gdni -> gde_interface
* Deprecates GDNative in favor of a simpler, lower level interface.
* New extension system allows registering core engine classes.
* Simple header interface in gdnative_interace.h
