'ArticlePageDataBefore': Before loading data of an article from the database.
&$wikiPage: WikiPage (object) that data will be loaded
&$fields: fields (array) to load from the database
+&$tables: tables (array) to load from the database
+&$joinConds: join conditions (array) to load from the database
'ArticlePrepareTextForEdit': Called when preparing text to be saved.
$wikiPage: the WikiPage being saved