HBASE-9579 Sanity check visiblity and audience for server-side modules


git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1525055 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9585 Update javadoc builder in pom to exclude empty packages in user api javadoc


git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1525059 13f79535-47bb-0310-9956-ffa450edef68
Add a bit of doc on what happens if old client connects to 0.96 cluster

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1525067 13f79535-47bb-0310-9956-ffa450edef68