Log Message:
Changes 2.0.13:
* Added "doveadm index" command to add unindexed messages into
  index/cache. If full text search is enabled, it also adds unindexed
  messages to the fts database.
* added "doveadm director dump" command.
* pop3: Added support for showing messages in "POP3 order", which can
  be different from IMAP message order. This can be useful for
  migrations from other servers. Implemented it for Maildir as 'O'
  field in dovecot-uidlist.
* doveconf: Fixed a wrong "subsection has ssl=yes" warning.
* mdbox purge: Fixed wrong warning about corrupted extrefs.
* sdbox: INBOX GUID changed when INBOX was autocreated, leading to
  trouble with dsync.
* script-login binary wasn't actually dropping privileges to the
  user/group/chroot specified by its service settings.
* Fixed potential crashes and other problems when parsing header names
  that contained NUL characters.