[WIP] Parse override tag arguments exactly like VSFilter

**This is the master issue for all your argument parsing bugs.**

Creating this pull request just so we can have this master issue, even though the code isn’t presentable. And I mean it: just look at that faux C++. Do note and comment on my `tag` macro though; I think it’s pretty nice.

Although actually, isn’t it almost done? Maybe I’ll try to finish it quickly. Maybe.