removed special handling of stats and server.log file

Stats should now just be log messages with `op:"stat"`.
Logs are only written to stderr. Handle any extra log IO
outside of the server process.
removed extra log config options
Merge branch 'master' into cassy

Conflicts:
	scripts/start-local.sh
Merge pull request #183 from dannycoates/cassy

Add date/timestamps to key_server.js.log