Removes Scene::getLightColor/setLightColor and Scene::getLightDirection/...

...getLightDirection since scene can have multiple lights.

Removes auto bindings for SCENE_LIGHT_COLOR and SCENE_LIGHT_DIRECTION. They must be set by developer with the preferred light to use.
Changes SceneLoader to ignore loading lightColor and lightDirection properties in a .scene file.
Fixes #1200
Fixes #1201