dbmail 2.0 release candidate 4

DBMail 2.0 Release Candidate 4 can be downloaded from the download page 
at http://www.dbmail.org. These bugs were fixed:

    * LMTP now works, also with cached connections. It turned we were 
misinterpreting some things in the RFC
    * Mozilla clients now work. It turned out that there were some 
errors in our ACL code
    * MD5 calculations were fixed. It turned out we were running into 
some problems with the endiannes on certain CPUs (fix by Aaron Stone and 
Leif Jackson)
    * Aaron Stone optimized message insertion and IMAP COPY.
    * Messages with headers bigger than 512kB were silently dropped. 
Currently, messages with such large headers are now bounced. They 
probably should be accepted in the future (although anyone sending 
messages that large is either insane or very evil!)

We could probably do with some more optimizations in the queries, but 
other than that, we're well on our way to a stable release!

Again, I would like to thank all people who have contributed code, bug 
reports and ideas!