* Move export/exportnowrap handling code out of the if(count($pages)) branch
* Add an error fallback to ApiFormatRaw (exportnowrap uses the XML formatter for errors), since Raw doesn't know how to format errors
* Accessed through the export and exportnowrap parameters added to action=query
* To facilitate &exportnowrap, add ApiFormatRaw, a formatter that just spits out its input without any formatting (not accessible through &format= of course)
* Fix up the action=query description message to reflect the deprecation of query.php