* 0 is falsy, cover for that case
* Add comments explaining the numbers, these come from PHP constants, via $wgCategoryTreePageCategoryOptions end up in data- attributes
* Follow-up r112849
* Use dashes versions of data attributes to make it easier to find them (now the data attributes as found in PHP where no where to be found in any JS file, appeared to be bogus)
* Don't create a new <div> element ($parentTag) only to store a single string in it's data object, using local variables for ctTitle, ctMode and ctOptions instead.
There's a couple of WTF moments in the code, this is really due to some issues with the PHP side of stuff. It really needs some TLC but for right now it works, I'll come back to it before 1.19 and clean it up.