-/**
- * The "Categoryfinder" class takes a list of articles, creates an internal representation of all their parent
- * categories (as well as parents of parents etc.). From this representation, it determines which of these articles
- * are in one or all of a given subset of categories.
- *
- * Example use :
- *
- * # Determines wether the article with the page_id 12345 is in both
- * # "Category 1" and "Category 2" or their subcategories, respectively
- *
- * $cf = new Categoryfinder ;
- * $cf->seed (
- * array ( 12345 ) ,
- * array ( "Category 1","Category 2" ) ,
- * "AND"
- * ) ;
- * $a = $cf->run() ;
- * print implode ( "," , $a ) ;
- *
- *
- */