BUG 57346 Summariser : The + (difference) reports show wrong elapsed time and throughput
Remove useless index field
Add javadocs
Add Apache License Header
Bugzilla Id: 57346

git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1648204 13f79535-47bb-0310-9956-ffa450edef68