kea-dhcp6
        added support for max-reconnect-tries and reconnect-wait-time
        to lease and host db parsers

        Added a callback for when DB backends detect loss of connectivity

        Added a self-rescheduling method to attempt to reconnect to the
        backends if retries are enabled

    dhcpsrv
        PgSqlConnection::checkStatementError() - Modified "fatal" logic
        to throw after invoking db_lost_callback.

    Misc. cleanup