Clarify doc on Synchronizing Timer
Clarify doc on Synchronizing Timer

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1611712 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: 5fa8beb9f728374ff805429529315601dab59ef0
etnetera/jmeter,apache/jmeter,etnetera/jmeter,ham1/jmeter,apache/jmeter,apache/jmeter,benbenw/jmeter,etnetera/jmeter,ham1/jmeter,apache/jmeter,ham1/jmeter,etnetera/jmeter,ham1/jmeter,benbenw/jmeter,benbenw/jmeter,etnetera/jmeter,apache/jmeter,ham1/jmeter,benbenw/jmeter