Log Message:
Changes 2.2.4:
+ doveadm: Added "flags" command to modify message flags.
+ doveadm: Added "deduplicate" command to expunge message duplicates.
+ dsync: Show the state in process title with verbose_proctitle=yes.
- imap/pop3 proxy: Master user logins were broken in v2.2.3
- sdbox/mdbox: A corrupted index header with wrong size was never
  automatically fixed in v2.2.3.
- mbox: Fixed assert-crashes related to locking