By default, an unhandled exception will cause the application to be terminated; but the project setting `mono/unhandled_exception_policy` was added to change this behaviour.
The editor is hard-coded to never terminate because of unhandled exceptions, as that would make writing editor plugins a painful task, and we cannot kill the editor because of a mistake in a thirdparty plugin.
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.
