See mostly the git repository.
* 1.21 - change shift to (...) = @_ form. update docs to better show
how to use the interface.
* 1.20 - BSD license, don't support Haiku OS (no link()), more web
pages on how various filesystems make rename() problematic.
* 1.18 - Changes from stdweird: octal mode support, :group support for
_set_ownership, backup suffix, mtime modifiction.