During and following the work on JDK-8314147, new features were added locally to the 3D lighting test tool:
* ability to take a snapshot of the 3D scene
* ability to use images as material maps (not just a solid color), included a default image
* ability to change the background (like the maps)
* added more test models (not just the 3 boxes)
* visual updates for the buttons and other controls
* refactoring to adjust to the features list this app supports now

They should be pushed into the repo.