add Load Managment Stats to Packets

#From https://github.com/freenet/fred/blob/cbfae4ae632608f82e5eeaf9a115588b32014c3a/src/freenet/node/NewPacketFormat.java#L637
if(!(addStatsBulk || addStatsRT)) break;

if(addStatsBulk) {
  MessageItem item = pn.makeLoadStats(false, false, true);
  if(item != null) {
    byte[] buf = item.getData();
    haveAddedStatsBulk = buf;
    // FIXME if this fails, drop some messages.
    packet.addLossyMessage(buf, maxPacketSize);
  }
}

if(addStatsRT) {
  MessageItem item = pn.makeLoadStats(true, false, true);
  if(item != null) {
    byte[] buf = item.getData();
    haveAddedStatsRT = buf;
    // FIXME if this fails, drop some messages.
    packet.addLossyMessage(buf, maxPacketSize);
  }
}
#-----------------
/** Related note by TS-PI

"The good news is that the DMT messages are still there, and none of the underlying functions looks like they've been deleted, and NPF will aggressively try to send stats whenever there's room in a packet to do so... https://github.com/freenet/fred/blob/master/src/freenet/node/NewPacketFormat.java#L637" --     SSK@8kCqlpKwsXackbaIm7PI71gTfgRzZZScud4qfg8qcEU,6xAFCWENTik96iQyCuqRsYkWKbyhbpfdDUM22c71tqI,AQACAAE/ Re: Regarding Peer Count on 2018-10-05 18:30:09  from freenet board on fms (a usenet like plugin for freenet) */