broccoli realtime transpile, testing and sandbox

This turned out even better than I hoped.

Fetch latest dev, from your ractive dir install new dev-deps:
```sh
$ npm install
```
From then on simply run:
```sh
$ broccoli serve
```
Default server is `http://localhost:4200/`, so `localhost:4200/test/tests` runs all qunit.

I left the transpiled src at `.amd`. You can go to `localhost:4200/sandbox/whatever/` to run sandbox, just _make sure you change to the `.amd` directory_ in your sandbox pages.

Okay, here's the really cool part, with [chrome livereload plugin](https://chrome.google.com/webstore/detail/livereload/jnihajbhpnppcggbcgedagnkighmdlei) installed, turn on and __your pages will auto refresh on save from the IDE!__