dnsreplay had odd race conditions in sending/reseinding packets
We had logic to pre-read the first packet for better error reporting, and then not read it at the top of the while loop,
but process the pre-read packet. However, this logic kept engaging, causing us to retransmit the previous packet a lot, depending
on the size of our retransmit window, which in turn depended on the receiver characteristic. Horrible.
dnsreplay may previously have overstated the number of duplicate packets because of this.
Merge branch 'master' of github.com:PowerDNS/pdns