[Dovecot] Apple patches 6-8

[Mike Abbott]

> If you start renaming API functions, rename all of them for  
> consistency. :)

Agreed, but when changing code on a branch, minimizing code deltas  
makes merging easier.

> Your code disabled idle timeout entirely

Yeah, probably not a good idea.  If I had realized that I probably  
would have just dropped the connection after N failed auth attempts,  
and chosen N for when it matched the idle timeout.  Your solution of  
clamping the backoff to just under the idle timeout is fine too.

PS -- Today is busy so I'll try to submit the next patches Monday or  
Tuesday.