Log Message:
Update to dovecot-1.0rc15.  From the release announcement mail:

	* Fixed an off-by-one buffer overflow in cache file handling. The
	  code is executed only with mmap_disable=yes and only if index files
	  are used (ie. INDEX=MEMORY is safe).
	* passdb checkpassword: Handle vpopmail's non-standard exit codes.

	- rc14 sometimes assert-crashed if .log.2 file existed in a mailbox
	  (earlier versions leaked memory and file descriptors)
	- io_add() assert-crashfixes
	- Potential SSL hang fix at the beginning of the connection

For details on the security issue, see:
http://www.dovecot.org/list/dovecot-news/2006-November/000023.html