8.2

#35 Refactor JvmProcessMemory to use FileLines - simpler implementation
#32 ENH: Add MetricManager.registerCGroupMetrics() ... to collect cgroup memory and cpu metrics
#33 Refactor rename registerJvmProcessMemoryMetrics() to registerProcessMemoryMetrics()
#34 Use Gauge long values for os load and heap percentage
#27 Simplify with TimedMetric.operationErr()
#28 Simplify removing use of @timed fullName
#29 Rename internal AlreadyEnhancedMarker to MetricsEnhanced
#30 Default to use a "app." prefix for derived metric names (best practice for ease of rollup)
#31 Refactor rename MetricManager methods getTimedMetric() -> timed() etc