Added minimum usage to make sure that numProcessers is always 1 or greater
Added minimum usage to make sure that numProcessers is always 1 or greater

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