Provide support to display a SimpleApplication into a JavaFX's ImageView.

 The core is SceneProcessorCopyToImageView + JmeContextOffscreenSurface
JmeForImageView is a helper class use to hide common boilerplate (I create it after my 3rd setup).
TestDisplayInImageView is a sample where user can change background color, change framerate (1-200), show/hide stats.

There some TODO and FIXME, but the current code is usable, try the TestDisplayInImageView (only crash during resize with 30+ framerate, The main FIXME).

The code is based on SDK SceneViewer and usage of AwtJmeContext.