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
public INavigatorContentDescriptor[] bindExtensions(String[] extensionIds,
			boolean isRoot) {
		if (extensionIds == null || extensionIds.length == 0) {
			return NO_DESCRIPTORS;
		}
		for (int i = 0; i < extensionIds.length; i++) {
			assistant.bindExtensions(extensionIds, isRoot);
		}
		Set boundDescriptors = new HashSet();
		INavigatorContentDescriptor descriptor;
		for (int i = 0; i < extensionIds.length; i++) {
			descriptor = CONTENT_DESCRIPTOR_REGISTRY
					.getContentDescriptor(extensionIds[i]);
			if (descriptor != null) {
				boundDescriptors.add(descriptor);
			}
		}
		if (boundDescriptors.size() == 0) {
			return NO_DESCRIPTORS;
		}
		return (INavigatorContentDescriptor[]) boundDescriptors
				.toArray(new INavigatorContentDescriptor[boundDescriptors
						.size()]);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.internal.navigator.INavigatorContentService#createCommonContentProvider()
	 */
	public ITreeContentProvider createCommonContentProvider() {