rtRemote - Exponential backoff in connection

[jmgasper]

From the recent review:

Should do standard exponential backoff instead of fixed 10 ms retry in your remote object search loop:       

if (diff >= RTEnvironment.FIND_OBBJECT_TIME) {
          totalTime += RTEnvironment.FIND_OBBJECT_TIME;
          logger.debug("searching object " + name + ", cost = " + totalTime / 1000.0 + "s");
          socketOut.send(new DatagramPacket(buff, buff.length, group, port));
          preCheckTime = now;
        }