Log Message:
Update from 2.5.2 to 2.5.3. From the announcement message:

A new version of dkim-milter is now available for download from SourceForge.

This release contains mainly bug fixes and additional diagnostic
information.  Two are correctness bugs with parsing of the signature tags,
so an upgrade is recommended.

The formal release notes entry:

2.5.3           2008/04/14
        Add "AllowSHA1Only" configuration option which permits operation
                of verifiers that only know about SHA1.  Without this, a
                filter compiled with only SHA1 support will refuse to start
                in verifier mode.
        Add "LogWhy" configuration parameter and "-W" \ 
command line flag
                to request detailed logging about why a message was not
                signed by the filter.  Intended for debugging; not intended
                for normal operation.
        Another tweak to parameters passed to db->open().  Based on patches
                from Jukka Salmi and S. Moonesamy.
        Fixes in ares_parse() to match the current syntax.  In particular,
                deal with the fact that some of our tokens can legally appear
                in e-mail addresses.  Problem noted by S. Moonesamy of
                Eland Systems.
        LIBDKIM: Evaluate key granularity against the "i=" value \ 
rather than
                the value of the From: header per RFC4871.  Problem noted by
                Jason Long.
        LIBDKIM: Remove the chartable stuff from dkim-tables.c as it is
                not used anywhere.
        LIBDKIM: Fix bug #SF1940302: Perform stronger validation of the value
                of the "h=" tag.