Bug 295981 [Forms] FormImages & FormFonts are not disposed correctly
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/internal/forms/widgets/FormHeading.java
public void setTextBackground(Color[] gradientColors, int[] percents,
			boolean vertical) {
		if (gradientColors != null) {
			gradientInfo = new GradientInfo();
			gradientInfo.gradientColors = gradientColors;
			gradientInfo.percents = percents;
			gradientInfo.vertical = vertical;
			setBackground(null);
			updateGradientImage();
		} else {
			
			gradientInfo = null;
			if (gradientImage != null) {
				FormImages.getInstance().markFinished(gradientImage);
				gradientImage = null;
				setBackgroundImage(null);
			}
		}
	}
	public void setHeadingBackgroundImage(Image image) {
		this.backgroundImage = image;
		if (image != null)
			setBackground(null);
		if (isBackgroundImageTiled()) {
			setBackgroundImage(image);
		} else
			updateGradientImage();
	}
	public Image getHeadingBackgroundImage() {
		return backgroundImage;