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
* Title area fields
	 */
	public static final String PREF_DLG_TITLE_IMG = "preference_dialog_title_image"; 
	static {
		ImageRegistry reg = JFaceResources.getImageRegistry();
		reg.put(PREF_DLG_TITLE_IMG, ImageDescriptor.createFromFile(PreferenceDialog.class,
				"images/pref_dialog_title.gif")); 
	}
	/**
	 * The current preference page, or <code>null</code> if there is none.
	 */
	private IPreferencePage currentPage;
	private DialogMessageArea messageArea;
	/**
	 * Indicates whether help is available; <code>false</code> by default.'
	 * 
	 * @see #setHelpAvailable
	 */
	private boolean isHelpAvailable = false;
	private Point lastShellSize;
	private IPreferenceNode lastSuccessfulNode;
	/**
	 * The minimum page size; 400 by 400 by default.
	 * 
	 * @see #setMinimumPageSize(Point)
	 */
	private Point minimumPageSize = new Point(400, 400);
	/**
	 * The OK button.
	 */