Mention use of softwareupdate utility. Fix #150.
Mention use of softwareupdate utility. Fix #150.
drduh/macOS-Security-and-Privacy-Guide,ScheerMT/OS-X-Yosemite-Security-and-Privacy-Guide,drduh/OS-X-Security-and-Privacy-Guide,DeadLion/macOS-Security-and-Privacy-Guide,drduh/OS-X-Yosemite-Security-and-Privacy-Guide