support memory profiling
support memory profiling

shawnbutts/statsdaemon,vimeo/statsdaemon,nejec/statsdaemon,vimeo/statsdaemon,raintank/statsdaemon,Huangyan9188/statsdaemon,raintank/statsdaemon,vimeo/statsdaemon,raintank/statsdaemon,ctdk/statsdaemon,deepglint/statsdaemon