This, as a dependency of xmake, contains files generated by xmake, which serves
as loop breaker of xmake.

Build without xmake:

1. Run `xmake f --exception=y --small=n --menu` and press save
2. Copy tbox.config.h from build/linux/x86_64/release
3. Run `xmake project -k cmake` and manually update debian/CMakeLists.txt
