scene fog seems not supported

[Vinc3r]

you can test using this code:

  _r.ready(function(){
        /* DEBUG FOG */

        var usePatch = false;
        if (usePatch) {
            _r.patch([{
                "scene": {
                    "fogMode": BABYLON.Scene.FOGMODE_LINEAR,
                    "fogStart": 1,
                    "fogEnd": 5,
                    "fogColor": "red"
                }
            }]);
        } else {

            _r.scene.fogMode = BABYLON.Scene.FOGMODE_LINEAR;
            _r.scene.fogStart = 1;
            _r.scene.fogEnd = 5;
            _r.scene.fogColor = _r.color("red");
        }
        /******/
});

[fabsharp]

may be the same problem as #20