Bug 94674 [Preferences] Preferences dialog separator under Title for pages does not stretch all the way across
The separator under the Header title for a preference page should stretch from the border of the sash to the far right with no margins in between.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
private Button okButton;
	/**
	 * The Composite in which a page is shown.
	 */
	private Composite pageContainer;
	/**
	 * The preference manager.
	 */
	private PreferenceManager preferenceManager;
	/**
	 * Flag for the presence of the error message.
	 */
	private boolean showingError = false;
	/**
	 * Preference store, initially <code>null</code> meaning none.
	 * 
	 * @see #setPreferenceStore
	 */
	private IPreferenceStore preferenceStore;
	private Composite titleArea;
	/**
	 * The tree viewer.
	 */
	private TreeViewer treeViewer;
	
    private ListenerList pageChangedListeners = new ListenerList(3);
	/**
	 * Creates a new preference dialog under the control of the given preference
	 * manager.
	 *