Added default file in case no file arguments are provided.  Changed to use  standard ThreadingHandler by default.
Added default file in case no file arguments are provided.  Changed to use 
standard ThreadingHandler by default.


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