* Committed some refactors to HTMLForm, along with a way to list and clear all stashed files from UploadStash. This was a feature I was trying to add Friday in an oh-wouldn't-this-be-helpful-while-debugging mood and it took way too long. Upside, at least now I understand MediaWiki's HTMLForm and other HTML classes, since I was trying to do everything the right way. Now, back to Roan's concurrency patch, which was the whole point of this.