[Dovecot] v2.1.16 released

http://dovecot.org/releases/2.1/dovecot-2.1.16.tar.gz http://dovecot.org/releases/2.1/dovecot-2.1.16.tar.gz.sig

+ Added quota-status policy service for Postfix
+ Added "doveadm batch" command to run multiple commands before moving
  onto the next user (useful only with -A and -u <usermask>)
+ Added forwards compatibility for v2.2 index files
- mdbox: Index rebuilding crashed in some situations
- Fixed a race condition with setting \Recent flags
- Fixed a crash when decoding a specific message (decoding is done
  for SEARCH TEXT/BODY and with full text search indexing, so this
  couldn't fully DoS a user)