ModeShape does not include "/jcr:system" content in query results

At this time, none of the content under "/jcr:system" is indexed or included in the query results. There doesn't appear to be anything in the spec that requires this (though it may be argued that it is content in the workspace, and therefore it too should be queryable). However, some of the JCR-SQL query test do expect to find the "/jcr:system" node in some of the query results.