[Dovecot] 1.0-test57

http://dovecot.org/test/

Two important fixes: the last one. I added more asserts anyway which try to catch similiar

• Fixes the recently reported dovecot-auth crashes with unexpected client input
• Fixes mbox corruption in some not-so-common cases. Hopefully this is

mistakes and avoid losing data.

Others:

• Added oe-ns-eoh workaround for pop3. Fixes outlook/netscape problems with buggy mails.
• lock_method = dotlock works now properly
• Cache file compression crashed in some situations
• auth_cache fixes from Andrey

Also I have about 80% of the code written for keywords support. It's about the last major missing feature from v1.0, so naming should change into 1.0-alphas soon. From there on it should be mostly about stabilization, cleaning up the code and maybe some optimization.