Add cpu_nbench test
	modified:   Makefile
	new file:   cpu_nbench/Makefile
	new file:   cpu_nbench/cpu_nbench_01.sh
	new file:   cpu_nbench/cpu_nbench_01.txt
	new file:   cpu_nbench/cpu_nbench_sanity.sh
	new file:   cpu_nbench/cpu_nbench_sanity.txt