Extracted the most minimal core initialization functionality from
`setup()` and `setup2()` so that `ClassDB` could be tested properly
(input, audio, rendering, physics etc, are excluded).
Display and rendering servers/singletons are not initialized at all.
Due to the fact that most subsystems are disabled, fixed various crashes in the
process (in order):
- `AcceptDialog` OK/cancel swap behavior (used `DisplayServer` while
`register_scene_types()`);
- `make_default_theme` which depends on `RenderingServer`;
- `XRServer` singleton access while calling `register_modules_types()`;
- hidden bug in a way joypads are cleaned up (MacOS and Linux only).
Removed manual `ClassDB` init/cleanup calls from `test_validate_testing.h`.
ClassDB tests:
Co-authored-by: Ignacio Etcheverry <ignalfonsore@gmail.com>
Happy new year to the wonderful Godot community!
We're starting a new decade with a well-established, non-profit, free
and open source game engine, and tons of further improvements in the
pipeline from hundreds of contributors.
Godot will keep getting better, and we're looking forward to all the
games that the community will keep developing and releasing with it.
Using `misc/scripts/fix_headers.py` on all Godot files.
Some missing header guards were added, and the header inclusion order
was fixed in the Bullet module.
