addeditdate doesn't do what it says

Created by: cotto

In the following query, %DATE% won't contain an article's edit date, even though addeditdate=true and ordermethod=lastedit are part of the query. With this patch, addeditdate acts as one would expect. I'm not sure how addeditdate ever worked so there's a chance that this is just a misunderstanding on my part.

{{#dpl: 
 title={{PAGENAMEE}}
 |namespace={{NAMESPACE}}
 |skipthispage=false
 |addeditdate=true
 |ordermethod=lastedit
 |userdateformat=U
 |format=,%DATE%,,
 |allowcachedresults=false
 |count=1
 |debug=4
}

edit: all of this happens on master as of 3.1.0.

Created by: Alexia

Looks good to me! Looking through the Article.php class code it looks like it was relying on an older feature in an old version of MediaWiki to work. It has support in there for the newer MediaWiki versions, but as you said it was not selecting it from the database. Looks like order direction still is not working correctly, but I will merge this then fix that.