From Wang Rui, "I modified the Serializer header to add a UPDATE_TO_VERSION_SCOPED

macro, which could set version within brackets and reset it after
that. All related serializers are also modified so that the
backward-compatibility bug reported by Farshid can be fixed.
"

From Robert Osfield, removed the use of osg::Referenced and creating the proxy object on the heap.

src/osgWrappers/serializers/osgVolume/Locator.cpp

@@ -42,8 +42,8 @@ REGISTER_OBJECT_WRAPPER( osgVolume_Locator,
     ADD_MATRIXD_SERIALIZER( Transform, osg::Matrixd() );  // _transform
 
     ADD_USER_SERIALIZER( LocatorCallbacks );
-    UPDATE_TO_VERSION( 90 )
     {
+        UPDATE_TO_VERSION_SCOPED( 90 )
         REMOVE_SERIALIZER( LocatorCallbacks );
     }
 }