[Dovecot] v2.0.6 released

http://dovecot.org/releases/2.0/dovecot-2.0.6.tar.gz http://dovecot.org/releases/2.0/dovecot-2.0.6.tar.gz.sig

* Pre-login CAPABILITY includes IDLE again. Mainly to make Blackberry
  servers happy.
* auth: auth_cache_negative_ttl default was 0 in earlier v2.0.x, but it
  was supposed to be 1 hour as in v1.x. Changed it back to 1h.
  If you want it disabled, make sure doveconf shows it as 0.

+ dbox: Added support for saving mail attachments to external files,
  with also support for single instance storage. This feature hasn't
  had much testing yet, so be careful with it.
+ doveadm: Added import command for importing mails from other storages.
+ Reduced NFS I/O operations for index file accesses
+ dbox, Maildir: When copying messages, copy also already cached fields
  from dovecot.index.cache
+ mdbox: Added mdbox_preallocate_space setting (Linux+ext3/XFS only)
- Maildir: LDA/LMTP assert-crashed sometimes when saving a mail.
- Fixed leaking fds when writing to dovecot.mailbox.log.
- Fixed rare dovecot.index.cache corruption
- IMAP: SEARCH YOUNGER/OLDER wasn't working correctly