Log Message:
Update to Dovecot 1.1beta11.

This one should be the last beta release before the first v1.1 release
candidate.

The main things left in my TODO are:

 - Squat indexes should handle expunges
 - Lucene indexes are broken
 - See if \recent flag handling could be fixed for maildir/mbox (it works for
   dbox though)
 - Some other minor things which I'll do if I have time, but won't block v1.1.0
   release.

Changes since beta10:

 - One major performance issue found and fixed. This was the main reason why we
   weren't yet in release candidate stage.
 - configure --with-package now gives an error if it can't find the necessary
   libs/headers for the package. Use --with-package=auto for the old behavior.
 - Memory leak fixes
 - Convert plugin fixes. Conversion is now done to namespace with INBOX.
 - Changes to handling group adding/removing to processes. Hopefully didn't
   break anything.
 - Message flag/keyword searches are now faster
 - Fixes/optimizations to handling SORT. After building initial indexes, my
   260k mail mailbox sorts in about 0.01 seconds. :)
 - Fixes to searching mails with unknown charsets/invalid data
 - deliver_log_format setting