Bug 133416 Open with references should only prompt if necessary
Build: I20060327-1200 While watching a demo at EclipseCon I noticed a user selecting "open project" on a workspace with only one project. It then prompted to ask if referenced projects should also be opened. This drew some laughter from the crowd - clearly it doesn't need to prompt if there is nothing to open. This is an easy polish item
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/actions/OpenResourceAction.java
IPreferenceStore store = IDEWorkbenchPlugin.getDefault()
				.getPreferenceStore();
		String key = IDEInternalPreferences.OPEN_REQUIRED_PROJECTS;
		String value = store.getString(key);
		if (MessageDialogWithToggle.ALWAYS.equals(value)) {
			return true;
		}
		if (MessageDialogWithToggle.NEVER.equals(value)) {
			return false;
		}
		String message = IDEWorkbenchMessages.OpenResourceAction_openRequiredProjects;
		MessageDialogWithToggle dialog = MessageDialogWithToggle
				.openYesNoCancelQuestion(getShell(), IDEWorkbenchMessages.Question, message, null,
						false, store, key);
		int result = dialog.getReturnCode();
		if (result == Window.CANCEL) {
			throw new OperationCanceledException();
		}
		return dialog.getReturnCode() == IDialogConstants.YES_ID;
	}
	/**
	 * Handles a resource changed event by updating the enablement if one of the
	 * selected projects is opened or closed.
	 */
	public void resourceChanged(IResourceChangeEvent event) {
		
		List sel = getSelectedResources();
		
		if (selectionIsOfType(IResource.PROJECT)) {
			IResourceDelta delta = event.getDelta();