When using the (currently undocumented) save command, go direct to the StoreConfig MBean because:
- It removes the dependency on StandardServer.
- It enables the Manager Servlet to detect if the feature is supported or not and show a useful error message.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1645471 13f79535-47bb-0310-9956-ffa450edef68