Documentation for theme_links should say that Attributes class must be an array

Issue Summary

API page: http://api.drupal.org/api/drupal/includes--theme.inc/function/theme_links/7

Describe the problem you have found:

attributes: (optional) Attributes for the anchor, or for the tag used in its place if no 'href' is supplied.

This needs to say that if class is supplied, it must be an array:

'attributes' => array(
'class' => array('colorbox-load'),
),

this will crash:

'attributes' => array(
'class' => 'colorbox-load',
),