percent-4xx-1m(-5m,-15m) metrics from metrics-jetty8 to metrics-jetty9
Merge pull request #713 from TheTweak/percent-metrics-jetty-9

percent-4xx-1m(-5m,-15m) metrics from metrics-jetty8 to metrics-jetty9
Add 4xx and 5xx ratio gauges to jetty9-legacy
Add counter for total elapsed time in Timer
Rename total time to total duration
Add total duration to all reporters