don't delete old javadocs when publishing site

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/weaver/trunk@1578252 13f79535-47bb-0310-9956-ffa450edef68
rework Javadocs availability

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/weaver/trunk@1578253 13f79535-47bb-0310-9956-ffa450edef68