adding newsyslog user and group permission for jenkins user

This fix is based on this issue: https://issues.jenkins-ci.org/browse/JENKINS-23543

Essentially, when newsyslog runs it will change the log to have root permissions. This causes will cause jenkins to silently fail and to not be able to restart on OSX. 

I have tested this change on Yosemite, Mavericks, and Mountain Lion.