Pull in release notes from 2.x-maintenance.
Pull in release notes from 2.x-maintenance.

ind9/metrics,gburton1/metrics,mspiegel/metrics,dropwizard/metrics,mveitas/metrics,fcrepo4-archive/metrics,timezra/metrics,egymgmbh/metrics,slachiewicz/metrics,ohr/metrics,thelastpickle/metrics,bentatham/metrics,kevintvh/metrics,randomstatistic/metrics,valery1707/dropwizard-metrics,jplock/metrics,slovdahl/metrics,mveitas/metrics,Banno/metrics,chenxianghua2014/metrics,mtakaki/metrics,mt0803/metrics,mattnelson/metrics,jasw/metrics,gburton1/metrics,infusionsoft/yammer-metrics,ChetnaChaudhari/metrics,tempredirect/metrics,rexren/metrics,wfxiang08/metrics,AltitudeDigital/metrics,cirrus-dev/metrics,fcrepo4-archive/metrics,mnuessler/metrics,dropwizard/metrics,signalfx/metrics,unitsofmeasurement/metrics,infusionsoft/yammer-metrics,dropwizard/metrics