Implement proper sorting of Postgres versioned directories
Summary:
Until now we had a special hack for 10.x series, but with the release of
Postgres 11, we need a more generic solution.
Reviewers: vkrause
Reviewed By: vkrause
Subscribers: kde-pim
Tags: KDE PIM
Differential Revision: https://phabricator.kde.org/D22274