Better panels, better tests, and other goodies

* NodeCG's config has moved to `cfg/nodecg.json`
* Dashboard panels are now defined in `dashboard/panels.json`
 * Panels now only define the panel body. The header is generated by NodeCG.
 * Panels may be written in [Jade](http://jade-lang.com/), allowing them to make compile-time decisions based on values present in `bundleConfig` and `ncgConfig`
 * Panel javascript now has access to a `$bundle` helper variable that allows for easy scoping of code
* Tests have been largely re-written
 * Tests are done with an actual bundle, not an emulated one
 * Extension, dashboard, and view APIs are all tested
 * Dashboard is now tested for panel rendering
* Added pretty colors to console logging
* Documentation has moved to the [wiki](https://github.com/nodecg/nodecg/wiki)