Add sun.misc as an optional OSGi import.
Add sun.misc as an optional OSGi import.

(It's not really optional.)

Closes #397.

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