Implement getStats() in connectors/bftsmart.js

[bergerch]

The method is not yet implemented. I think the following behavior would be necessary:

• Throughput. This is parsed from the logs of the leader (replica 0): The Throughput is the average throughput of all measurements except the first and last measurement. MaxThroughput is the max value.
• Client. If possible I want the following behavior:
  -- If the network is uniform, just read the avg latency (-10%) and avg latency from the first client. This becomes latencyOutlinerRemoved and latency respectiveley
  -- (to be discussed:) if AWS, for each region, read avg latency (-10%) of the first client placed into the region (o.e. for every host) and write it into the results.csv. The results.csv has thus a column for every client-region to show the client latency obtained from that region.
• Finally, run killall java to clean JVMs that are not terminate in-time by Shadow