Prettify generated CLJS files as per issue #2

Uses the ```clojure.pprint/write``` with a ```code-dispatch``` to format the clojurescript forms - the example given in issue #2 is now output as:

```clojure
;; This file was generated with lein-dalap from
;;
;; src/wireframes/renderer/color.clj @ Tue Feb 11 21:26:31 GMT 2014
;;
(ns wireframes.renderer.color
  (:require [wireframes.renderer.lighting :refer [default-position
                                                  positional-lighting-decorator]]
            [inkspot.color :refer [coerce red green blue alpha]]
            [inkspot.color-chart :refer [spectrum color-mapper]]))

(defn tee [f] (fn [x] (f x) x))

(defn dup [x] [x x])
```

Which is slightly different from the original source... but it'll be fine, as the main motivation was to be able to use browser debugging on source maps.

Also, updated the *lein-cljsbuild* version to latest.