Added support for filename only setup of CompositeLayer on reading/writing.
Added support for filename only setup of CompositeLayer on reading/writing.


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