Added computeDataVariance method into osg::Object and implementations in Drawable and StateSet,

and calling of osgUtil::StaticObjectDetectionVisitor in osgViewer::Viewer

src/osgWrappers/osg/CullFace.cpp

@@ -30,7 +30,7 @@ BEGIN_ENUM_REFLECTOR(osg::CullFace::Mode)
 	I_EnumLabel(osg::CullFace::FRONT_AND_BACK);
 END_REFLECTOR
 
-BEGIN_ABSTRACT_OBJECT_REFLECTOR(osg::CullFace)
+BEGIN_OBJECT_REFLECTOR(osg::CullFace)
 	I_BaseType(osg::StateAttribute);
 	I_ConstructorWithDefaults1(IN, osg::CullFace::Mode, mode, osg::CullFace::BACK,
 	                           Properties::NON_EXPLICIT,