Bug 137315 [Dialogs] Doubleclickable area to restore dialog size is often very small
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/Dialog.java
if (defaultButton) {
			Shell shell = parent.getShell();
			if (shell != null) {
				shell.setDefaultButton(button);
			}
		}
		buttons.put(new Integer(id), button);
		setButtonLayoutData(button);
		return button;
	}
	/**
	 * Creates and returns the contents of this dialog's button bar.
	 * <p>
	 * The <code>Dialog</code> implementation of this framework method lays
	 * out a button bar and calls the <code>createButtonsForButtonBar</code>
	 * framework method to populate it. Subclasses may override.
	 * </p>
	 * <p>
	 * The returned control's layout data must be an instance of
	 * <code>GridData</code>.
	 * </p>
	 * 
	 * @param parent
	 *            the parent composite to contain the button bar
	 * @return the button bar control
	 */
	protected Control createButtonBar(Composite parent) {
		Composite composite = new Composite(parent, SWT.NONE);