Make two successive modifications of the same attribute separate. This
lets the consumer interpret the log entry the same way as the server
that produced it.
Still depends on the log entry attributes being read in the same order
as they were written.
Simplifies tests for the DB storage backends.
Adds indexing etc to ndb in some cases, to match bdb/hdb.
This also fixes some broken back-null/back-ldif settings.
add hex timestamp to lutil_debug() output
Fix LASTMOD race condition in accesslog.c
Set refreshInterval even if using refreshAndPersist, since
fallbacks will use refresh params