Add func to convert Sys100NStoEpoch. Try to make Win CPU monitoring accurate

Just doing this section for now. If the spikes are gone that appear in https://github.com/StackExchange/scollector/issues/21 then can role it out to more servers. Then when I am sure it works, can go and start updating the rest of the collectors
Merge branch 'master' into timestamp_100NS
Merge pull request #85 from StackExchange/timestamp_100NS

Timestamp 100 ns