Converting deliver.db from berkely-nosync to skiplist

[Brenden Conte]

Using RPM version of 2.2.10 and Berkeley DB 4.1.25...

We've run into problems the last few nights with corruption of the 
duplicate delivery database (delivery.db).   I tried disabling it, however 
that caused processes to fail to communicate to the local lmtp sockets for 
some reason.  We do enjoy this feature, and disabling it was no the optimal 
solution, so we would like to convert it to skiplist.

Also, I noted in the man page that it also includes sieve in the 
description for that option.  I was unaware of any sieve database - where 
is it (or is it old, left over from previous versions)?

Thanks,
Brenden