Clarify doc as per sebb note
Clarify doc as per sebb note

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1416175 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: 86718f4786ff21203b1e8c6945c9733084dea6b6
etnetera/jmeter,ham1/jmeter,ham1/jmeter,ham1/jmeter,etnetera/jmeter,benbenw/jmeter,apache/jmeter,etnetera/jmeter,apache/jmeter,apache/jmeter,etnetera/jmeter,benbenw/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter,apache/jmeter,etnetera/jmeter,benbenw/jmeter,ham1/jmeter