Reference to JAI in API and javadocs

[jodygarnett]

I am not quite sure how to balance between:

• Offering an easy migration path for projects porting from JAI
• Removing JAI references from documentation and API to prevent confusion

My best idea is to deprecate methods and classes that reference JAI while introducing ImageN replacements:

public class ImageN {
   // JAI Core
  protected static final int HINT_IMAGE_LAYOUT = 101;
  ...
  public static RenderingHints.Key KEY_IMAGE_LAYOUT =
     new RenderingKey(HINT_IMAGE_LAYOUT, ImageLayout.class);
}

/**
 *
 * @deprecated Use ImageN
 */
public final class JAI extends ImageN {
   ....
}

There is also something to be said for just just going directly to ImageN.