Removal of quasi-public" methods for renderToImage and BufferedImage conversion

[Kevin Rushforth]

This is a heads-up about a change coming in JavaFX 8 next week in b73:

http://javafx-jira.kenai.com/browse/RT-27479

This change will remove the following "quasi-public" methods from FX 8 
(all of which have equivalent public API methods that were added in FX 2.2):

Scene:
   renderToImage(Object)
   renderToImage(Object,float)

Image:
   impl_toExternalImage(Object)
   impl_fromExternalImage(Object)
   impl_isExternalFormatSupported(Class)

If you use any of the above methods, you will need to migrate to the new 
methods: snapshot in place of renderToImage and 
SwingFXUtils.toFXImage/fromFXImage in place of 
impl_fromExternalImage/impl_toExternalImage.

Let me know if you have any questions.

Thanks.

-- Kevin