Fixed bug where the Optimizer::StateVisitor was trying to optimize non existant StateSet's.
Fixed bug where the Optimizer::StateVisitor was trying to optimize
non existant StateSet's.


artoolkit/osg,openscenegraph/osg,jtorresfabra/osg,scrawl/osg,scrawl/osg,tomasthoresen/osg,scrawl/osg,marchelbling/osg,artoolkit/osg,tomasthoresen/osg,jtorresfabra/osg,openscenegraph/osg,artoolkit/osg,scrawl/osg,jtorresfabra/osg,tomasthoresen/osg,openscenegraph/osg,marchelbling/osg,marchelbling/osg,artoolkit/osg,jtorresfabra/osg,tomasthoresen/osg,marchelbling/osg,openscenegraph/osg