Extension:Article Class Extended

This extension extends the Mediawiki Article class with the following features:
 * Serves XML / XSL data sources stored in MW pages with proper MIME content type (requires using Extension:XML Class)
 * Serves 'raw' data stored in MW pages, the said data must be enclosed in whereby defines the title name extension that will be used to retrieve the said data.
 * Adds a new hook ArticleViewEx which can be leveraged to modify content before it is added to the output page.