+ github: contributing guidelines.
= core: fix NPE when finishing segments, fixes #88
= core: remove a println left from testing
= play-examples: update kamon dependencies to snapshot until next release
! kamon-newrelic: * Avoid reporting data to Newrelic if no metrics have been collected
								  * Implement error handling with NewRelic Agent                                                                                                                          * Minor refactor                                                                                                                                                        * close issue #7 and issue #17
! build: upgrade dependencies.
= core: use explicitly thrown exceptions for failure tests.
= system-metrics: handling sigar.getLoadAverage gracefully on unsupported systems
! build: more version upgrades + include sbt-dependency-graph
+ core: provide sum and percentile functions in Histogram.Snapshot, closes #85
= kamon-newrelic: minor refactor when merge metrics
! kamon-core: Remove KamonWeaverMessageHandler to avoid dependencies issues and closes #97
+ system-metrics: introduce Context Switches(only for Linux) metrics and closes #66
+ log-reporter: introduce ContextSwitches metrics
= play-example: downgrade scala version in master to 2.10.4
= core: exclude CallerThreadDispatcher from instrumentation, change Dispatcher to MessageDispatcher in DispatcherInstrumentation  and fixes #95
= core,system.metrics: fixed serialization errors when using akka.actor.serialize-messages = on
= core: minor cleanup of the remoting instrumentation
+ akka-remote: create a new kamon-akka-remote module, closes #99
= system-metrics: make ContextSwitchesMetrics serializable