Bug 202316 [Forms] Add gradient sharing support for FormHeading
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/internal/forms/widgets/FormImages.java
private Image fImage;
		private int fCount;
		
		public ImageReference(Image image) {
			fImage = image;
			fCount = 1;
		}
		public Image getImage() {
			return fImage;
		}
		
		
		public boolean decCount() {
			return --fCount == 0;
		}
		public void incCount() {
			fCount++;
		}
	}
	
	public Image getGradient(Display display, Color color1, Color color2,