Bug 189636 Custom rule template failing
Null poonter exception being thrown when trying to add a custom rule which is causing the rule cretion to fail. Also there is a minor typo in the rule template string.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/internal/navigator/NavigatorContentService.java
* (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.navigator.INavigatorContentService#saveState(org.eclipse.ui.IMemento)
	 */
	public void saveState(IMemento aMemento) {
		synchronized (this) {
			for (Iterator extensionItr = getExtensions().iterator(); extensionItr
					.hasNext();) {
				NavigatorContentExtension element = (NavigatorContentExtension) extensionItr
						.next();
				element.saveState(aMemento);
			}
		}
	}
	public boolean isActive(String anExtensionId) {
		return assistant.isActive(anExtensionId);
	}
	public boolean isVisible(String anExtensionId) {
		return assistant.isVisible(anExtensionId);
	}
	protected final Collection getExtensions() {
		return (contentExtensions.size() > 0) ? Collections
				.unmodifiableCollection(contentExtensions.values())
				: Collections.EMPTY_LIST;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.navigator.INavigatorContentService#addListener(org.eclipse.ui.internal.navigator.extensions.INavigatorContentServiceListener)
	 */