On the main tag listing, for child tags, you only get an unlink
button on hover. So if you want to delete a child tag you'd have to
unlink, then refresh, then delete. Now you can just go to its page
and delete it there.
This will help keep the code on the pages focused more on the
page-specific stuff like form handling, and less on the raw api.
Plus, by having it all in one place, it can be cached
and also we can use any api from within any page.
