[Dovecot] v1.2.11 released

http://dovecot.org/releases/1.2/dovecot-1.2.11.tar.gz http://dovecot.org/releases/1.2/dovecot-1.2.11.tar.gz.sig

mbox users really should upgrade, because by sending a message with a huge header you could basically cause a DoS (this problem exists only with v1.2.x, not with v1.0 or v1.1).

- mbox: Message header reading was unnecessarily slow. Fetching a
  huge header could have resulted in Dovecot eating a lot of CPU.
  Also searching messages was much slower than necessary.
- mbox, dbox, cydir: Mail root directory was created with 0770
  permissions, instead of 0700.
- maildir: Reading uidlist could have ended up in an infinite loop.
- IMAP IDLE: v1.2.7+ caused extra load by checking changes every
  0.5 seconds after a change had occurred in mailbox