Minor improvements to System Helper
Minor improvements to System Helper

* Return 0 if could not establish the number of CPUs
* Return 'N/A' if could not establish the RAM size
* Add argument hinting

QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp,QoboLtd/project-template-cakephp