Start indexing on stories_by_date.
Added a very basic gd_story_set().
New functions to get and set into a list in reverse order.
Added 'num' and 'offset' parameters to 'story_set'.
Added 'from' and 'to' to 'story_set'.
Added alternate orderings to 'story_set'.
Improved reordering output in 'story_set'.