Bug 296565 Make group creation an advanced option in the folder
bundles/org.eclipse.ui.ide/extensions/org/eclipse/ui/dialogs/WizardNewFolderMainPage.java
/**
	 * Checks whether the linked resource target is valid. Sets the error
	 * message accordingly and returns the status.
	 * 
	 * @return IStatus validation result from the CreateLinkedResourceGroup
	 */
	protected IStatus validateLinkedResource() {
		IPath containerPath = resourceGroup.getContainerFullPath();
		IPath newFolderPath = containerPath.append(resourceGroup.getResource());
		IFolder newFolderHandle = createFolderHandle(newFolderPath);
		IStatus status = linkedResourceGroup
				.validateLinkLocation(newFolderHandle);
		if (status.getSeverity() == IStatus.ERROR) {
			if (firstLinkCheck) {
				setMessage(status.getMessage());
			} else {
				setErrorMessage(status.getMessage());
			}
		} else if (status.getSeverity() == IStatus.WARNING) {
			setMessage(status.getMessage(), WARNING);
			setErrorMessage(null);
		}
		return status;
	}
	/**
	 * Returns whether this page's controls currently all contain valid values.
	 * 
	 * @return <code>true</code> if all controls are valid, and
	 *         <code>false</code> if at least one is invalid
	 */