In FlaggedRevs:

In FlaggedRevs:

* Moved the FlaggedRevs class to its own file
* Removed $wgFlaggedArticle, store an instance inside the Article object instead. Also store a reference in the Title object, since some hooks only have a Title available.
* Modified all hooks which were previously calling $wgFlaggedArticle directly to go via an instance loader function.
* Merged hook functions for ArticleViewHeader and DiffViewHeader
* Changed the way FlaggedRevs sets the right image version in ImagePage, to avoid a function call on startup
* Some coding style changes, such as consistent variable case, consistent indenting style, meaningful variable names, etc.
* Fixed typo in updateAutoPromote.php
* Removed the $wgFlaggedRevsVisible feature, this doesn't seem to be in keeping with our mission so I couldn't see the point in spending a lot of time fixing its bugs. Revert if necessary.
* Use Xml::encodeJsVar() to transfer data from PHP to JS, don't DIY
* Use OutputPage::addHeadItem() instead of an infinite-lifetime variable to ensure that only one copy of the header item is added. OutputPage objects may come and go.