dovecot updated to 2.2.20

- director: Backend tags weren't working correctly.
- ldap: tls_* settings weren't used for ldaps URIs.
- ldap, mysql: Fixed setting connect timeout.
- auth: userdb lookups via auth-worker couldn't change username
- dsync: Fixed handling deleted directories. Make sure we don't go to
  infinite mailbox renaming loop.
- imap: Fixed crash in NOTIFY when there were watched namespaces that
  didn't support NOTIFY.
- imap: After SETMETADATA was used, various commands (especially FETCH)
  could have started hanging when their output was large.
- stats: Idle sessions weren't refreshed often enough, causing stats
  process to forget them and log errors about unknown sessions when
  they were updated later.
- stats: Fixed "Duplicate session ID" errors when LMTP delivered to
  multiple recipients and fts_autoindex=yes.
- zlib plugin: Fixed copying causing cache corruption when zlib_save
  wasn't set, but the source message was compressed.
- fts-solr: Fixed escaping Solr query parameters.
- lmtp: quota_full_tempfail=yes was ignored with
  lmtp_rcpt_check_quota=yes

.gitignore

@@ -92,3 +92,4 @@ pigeonhole-snap0592366457df.tar.bz2
 /dovecot-2.2-pigeonhole-0.4.8.tar.gz
 /dovecot-2.2.19.tar.gz
 /dovecot-2.2-pigeonhole-0.4.9.tar.gz
+/dovecot-2.2.20.tar.gz