scene_util.js: make light constant attenuation work properly when zero, set linear & quadratic attenuation to zero by default
scene_util.js: make light constant attenuation work properly when zero, set linear & quadratic attenuation to zero by default

juanpiwi/magi,juanpiwi/magi,kig/magi,kig/magi,juanpiwi/magi,juanpiwi/magi,kig/magi