Bug 295981 [Forms] FormImages & FormFonts are not disposed correctly
bundles/org.eclipse.ui.forms/src/org/eclipse/ui/internal/forms/widgets/FormHeading.java
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.events.MouseEvent;
import org.eclipse.swt.events.MouseMoveListener;
import org.eclipse.swt.events.MouseTrackListener;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.FontMetrics;
import org.eclipse.swt.graphics.GC;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.graphics.Rectangle;
import org.eclipse.swt.widgets.Canvas;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Layout;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.ToolBar;
import org.eclipse.ui.forms.IFormColors;
import org.eclipse.ui.forms.IMessage;
import org.eclipse.ui.forms.events.IHyperlinkListener;
import org.eclipse.ui.forms.widgets.Hyperlink;
import org.eclipse.ui.forms.widgets.ILayoutExtension;
import org.eclipse.ui.forms.widgets.SizeCache;
import org.eclipse.ui.internal.forms.IMessageToolTipManager;
import org.eclipse.ui.internal.forms.MessageManager;
/**
 * Form header moved out of the form class.
 */
public class FormHeading extends Canvas {