Release is Coming

Still putting in some commits before we shove this next version out the door.

There was some fallout regarding Scene and some refactoring. There is a new interface for scenes called SceneRender that captures the render method that was just a public method of Scene, and new stuff for hooking the Scene to RenderContext; this got inverted out of RenderContext so we can have more control over things in other Scene subclasses, yet to be written. This made it all the way to SceneCompleteSentinel; anywhere it was Scene becomes SceneRender interface.

The Null Object design pattern gets called on in RenderService et al; this eliminates some null checks for a SceneRender that are on a per-frame path.