Refactors SC.SceneView to match the new SC.ContainerView

See this issue https://github.com/sproutcore/sproutcore/issues/1078 for more details about this.

Basically you can define two different transition plugins and transition options depending on if the animation is backwards or forwards.

I've took back the description of `SC.SceneView` before it were deprecated but I think it needs an update. If a native english speaker could do it, it would be better.

Note that it works like expected when using 'right' and 'left' directions but it doesn't when using 'top' and 'bottom'. I guess this is because of an issue with `SC.ContainerView` or something else.