Create Ember.libraries for keeping track of versions for debugging.

Ember registers its libraries and external libraries can register themselves, so given:

```javascript
Ember.libraries.register("Emberella", "0.0.1");
```

We get:
```text
DEBUG: -------------------------------
DEBUG: Ember.VERSION      : 1.0.0
DEBUG: Handlebars.VERSION : 1.0.0
DEBUG: jQuery.VERSION     : 1.10.2
DEBUG: Emberella.VERSION  : 0.0.1
DEBUG: ------------------------------- 
```