Document how to test

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/branches/4.3.x@1571310 13f79535-47bb-0310-9956-ffa450edef68
Remove duplicate clirr entry

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/branches/4.3.x@1571314 13f79535-47bb-0310-9956-ffa450edef68