* Add count() method to TitleArray and UserArray.

* Add count() method to TitleArray and UserArray.
* Change PageHistory::fetchRevisions() to return a result object instead of an array of rows.
* Stylistic issues: use foreach( $res as $row ) instead of while( $row = $dbr->fetchObject( $res ) ), change a couple of variable names, use __METHOD__.

There should be no functional changes.