+ datadog: more tests and support for multiple metrics in the same package
= core: fixes #37
Merge branch 'master' into release-0.3_scala-2.11
= core : fixes #38
* I've changed the way to get the Actorsystem inside of DispatcerTracing,  passing the actorSystem across the Dispatchers and then to each Dispatcher in the same ActorSystem.
= core: remove ContinuousHdrRecorder from ActorMetrics
* in the case that we get a negative number, change the number to positive in MinMaxCounter in order to avoid IndexOutOfBoundsException.
+ core: upgraded HDRHistogram to 1.2.1
= core: minor refactor in MinMaxCounter
Merge branch 'master' into release-0.3_scala-2.11