Display "delete" link for authorized users

This patch adds a "delete" link when a user is authorized to delete a comment. Only problem is that the link is displayed *last*, not first. That's because hook_link() does not support link weights, and comment_delete.module is called after comment.module. One way would be to adjust comment_delete.module's weight. Also check out this discussion about ordering links: http://drupal.org/node/44435