A single new feature: the new log-structured metadata store implementation, described
in the presentation from Moscow Highload'2025 (check it out [here](https://vitastor.io/en/docs/#talks-and-presentations)).
It's now the default store for new OSDs. The support for the old store is also left in place,
you can still choose it for new OSDs with `vitastor-disk prepare --meta_format 2`.
OSDs from previous versions with the old store format will also continue to operate just like before.
Vitaliy Filippov
a67c415e0f