Log Message:
Changes 2.2.6:
* acl: If public/shared namespace has a shared subscriptions file for
  all users, don't list subscription entries that are not visible to
  the user accessing it.
+ doveadm: Added "auth lookup" command for doing passdb lookup.
+ login_log_format_elements: Added %{orig_user}, %{orig_username}
  and %{orig_domain} expanding to the username exactly as sent by
  the client (before any changes auth process made).
+ Added ssl_prefer_server_ciphers setting.
+ auth_verbose_passwords: Log the password also for unknown users.
+ Linux: Added optional support for SO_REUSEPORT with
  inet_listener { reuse_port=yes }
- director: v2.2.5 changes caused "SYNC lost" errors
- dsync: Many fixes and error handling improvements
- doveadm -A: Don't waste CPU by doing a separate config lookup
  for each user
- Long-running ssl-params process no longer prevents Dovecot restart
- mbox: Fixed mailbox_list_index=yes to work correctly