* /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
* of this function would be set to "a/ab/Foo.png/120px-Foo.png".
* This method is responsible for turning that into an array
* /w/images/thumb/a/ab/Foo.png/120px-Foo.png. The $thumbRel parameter
* of this function would be set to "a/ab/Foo.png/120px-Foo.png".
* This method is responsible for turning that into an array
* * f => the filename (Foo.png)
* * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
* * archived => 1 (If the request is for an archived thumb)
* * f => the filename (Foo.png)
* * rel404 => the whole thing (a/ab/Foo.png/120px-Foo.png)
* * archived => 1 (If the request is for an archived thumb)