- Material class contained both 'shininess' and 'Ns' member variables
- 'Ns' and 'Ni' are initialized to 0 ('Ni' is unused at the moment)
- only 'Ns' was read from .mtl file but 'shininess' was used for osg::Material
- 'illum' was read from .mtl file but never used; it is now used as follows
-- illum==0 -> no osg::Material created/attached therefore no lighting
-- illum==1 -> osg::Material specular is set to black
-- illum==2 (default) -> specular read from .mtl file is used
- 'map_Kd' and 'map_Ks' may contain additional arguments (e.g. '-s 1 1 1'),
these are now skipped over and the texture filename is properly extracted
"
