This module implements the version 7 UUIDs, proposed by Peabody and
Davis in
https://www.ietf.org/id/draft-peabody-dispatch-new-uuid-format-02.html
as an extension to RFC4122.

Version 7 has the nice characteristic that the start of a UUID encodes
the time with a chronological sort order and potentially ~50ns time
resolution, while the end of the UUID includes sufficient random bits
to ensure consecutive UUIDs will remain unique.