Articles
========

Articles are text blocks stored in the database.  When the user
selects an article from a menu, the text is displayed to the user.

Articles may be linked to other articles in the same table.  In 
this case, pressing F7 gives the user the ability to navigate
to the previous or next article.

  `articles`
    article_id      Primary key.  Does not auto-increment.  This is the
                    same as the `reference_id` in the `toc` table.
    next_id         Key to `article_id` of next article in this chain,
                    or 0 if no next article.
    prev_id         Key to `article_id` of previous article in this chain,
                    or 0 if this is the first article in the chain.
    data            ASCII text of the article that is displayed to the user.


Adding an Article Chain (entry_type = MULTI_TEXT)
  
  The first article (or only article) in an article chain must have a
  row in the `toc` table.  That row must have an associated row in the
  `entry_types` table, and the `entry_type` must be 136 (MULTI_TEXT).

  Example:
    Main Menu > Customer Service Center > What's New
    
    "What's New" in the `toc` table:
      toc_id:       235
      menu_id:      4
      title:        What's New
      reference_id: 401
    
    "What's New" in the `entry_types` table:
      reference_id: 401
      entry_type:   136 (MULTI_TEXT)
      cost:         NORMAL
      special:      N
      
    First article of "What's New" chain in `articles` table:
      article_id:   401
      prev_id:      0
      next_id:      1000006
      data:         <text message>
    
    Next article of "What's New" chain in `articles` table:
      article_id:   1000006
      prev_id:      401
      next_id:      1000005 -- yes, its backwards(?)
      data:         <text message>
      
  Important:
    The first article in an article chain has associated rows in the
    `toc` and `entry_types` tables.  
    
    Each successive article in the chain does not have a row in the
    `toc` table.  However, it DOES have a row in the `entry_types` table.