lib/kernel: use the legacy NI for `Pointer::free` to work with nitg_0

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/file: fix whitespace errors

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/file: revamp API with `Path` and a nity `FileStat`

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>