add a convenient sirona cassandra shaded jar, if we want to use it directly in javaagent

git-svn-id: https://svn.apache.org/repos/asf/incubator/sirona/trunk@1570036 13f79535-47bb-0310-9956-ffa450edef68
shade plugin version in pluginManagement in top pom

git-svn-id: https://svn.apache.org/repos/asf/incubator/sirona/trunk@1570037 13f79535-47bb-0310-9956-ffa450edef68