of minutes in the past and reverted latest change. The export file dump
will now contain four data elements: f - first date of index entry write
date, l - last date of index write date, n - now-date of index dump
time, c - count of numbers inside the dump. '0N' denotes a series of
changes which will lead to the opportunity to exchange index data dumps
in a way that is needed to integrate ZeroNet index data. This will be
based on index dump sharing; that causes this commit.
