@dzucconi: Add profile icon UI & lots of little things

Mainly this is to get a profile icon to appear so one can logout and see their profile on Artsy, see below:

![image](https://cloud.githubusercontent.com/assets/555859/4427635/7414907c-45c1-11e4-8536-c53a98019b9e.png)

Other things include:

* Wire up Artsy API v2 to do auth (using straight [passport](https://github.com/jaredhanson/passport-github) for now b/c we don't need custom UI and can't use hardcoded urls (which artsy-passport does right now).
* Namespace layout .svg icons to avoid conflicts down the line
* Random organization refactors including splitting the /lib/setup.coffee into smaller modules like /lib/setup/env /lib/setup/config
* Refactor the `spooky_fetcher` lib into a `halbone` that is better suited to be open sourced at some point.
* Including _links and _embedded b/c v2's profile API returns the icon in `_links.thumbnail` so we can't really just drop those from being included in the Backbone model.
* A bit of work stubbing spooky & gravity APIs for tests

Sorry for the weird diff... I think I tried squashing commits and some old history is being included here.