Document -j option
Document -j option

git-svn-id: https://svn.apache.org/repos/asf/jakarta/jmeter/branches/rel-2-2@518540 13f79535-47bb-0310-9956-ffa450edef68

Former-commit-id: a75fc7a75878bcc45ac5666ae0a8696bf6d969ee
ham1/jmeter,benbenw/jmeter,ham1/jmeter,benbenw/jmeter,apache/jmeter,ham1/jmeter,apache/jmeter,benbenw/jmeter,ham1/jmeter,etnetera/jmeter,apache/jmeter,benbenw/jmeter,etnetera/jmeter,etnetera/jmeter,ham1/jmeter,apache/jmeter,apache/jmeter,etnetera/jmeter,etnetera/jmeter