[NGRINDER-562] Make per test TPS available if sampling interval is more
than 4.
Merge branch 'master' of https://github.com/nhnopensource/ngrinder.git

Conflicts:
	ngrinder-controller/pom.xml
	ngrinder-controller/src/main/java/org/ngrinder/perftest/controller/PerfTestController.java
	ngrinder-core/src/main/java/net/grinder/SingleConsole.java