[Watchdog] Use stackoverflow.com for DNS check

[Git] Ignore mail_plugins*
[Dovecot] Read mail_plugins from dynamically generated file
[Dovecot] Encrypt FTS
[Dovecot] Add break_imap_seach option to Solr
[Web] Add ability to send quarantine notification mails
[Web] Minor style fixes
[Web] Add new MAILBOX_DEFAULT_ATTRIBUTES (doc updates, anyone? :-( )
[Web] Use rcpt_smtp if rcpt_mime is not set
[Web] Other minor fixes