[MNG-2878] Adding an import from the maven core classrealm into the plugin classrealm, to allow retrieval of default-report.xml using getClass().getResourceAsStream(..) which is used in maven-reporting-impl 2.0...which in turn is used from checkstyle (at least).
maven/components/trunk/maven-core/src/main/java/org/apache/maven/plugin/DefaultPluginManager.java