Bug 57193: A few javadoc fixes
 * Remove self-closing br-tags by replacing them with a
   unordered list 
 * Add links to URL in javadaocs 
 * Add a return description in javadocs
Bugzilla Id: 57193


git-svn-id: https://svn.apache.org/repos/asf/jmeter/trunk@1639461 13f79535-47bb-0310-9956-ffa450edef68