Misc refactorings and updates.

Refactor to use threading in the app stack.
Update to latest clojure.
Add lein aliases for easier testing, and add to readme.
Use localhost:3000 callback for testing.
Reindent for emacs clojure-mode (sorry, it happened).

I can understand if you might not want some of these changes, but I figured I'd push them in case you did.