Ajax terms

I noticed the frontend was doing term typeahead by pulling in a big list of all terms from the backend and embedding them in the page.  I've switched it to use AJAX instead.

This led me down a path of self discovery, where I questioned the nature of my own existence, followed by the nature of vocabularies.  I think I'm OK, but not sure about vocabularies.  At any rate, I've also switched them not to send back the complete list of terms on every request, since we don't use them anymore.