Fix documentation and inconsistent usage for Ember.deprecateFunc()

<code>Ember.deprecateFunc(message, func)</code> doesn't actually do, in some places, what it was stated as doing as in the docs. The docs listed the second argument, func, as the function to be deprecated but twice it was called using the second argument as an alias to a new, non-deprecated function with the same functionality. 

Here are the two calls:
```javascript
Ember.none = Ember.deprecateFunc("Ember.none is deprecated. Please use Ember.isNone instead.", Ember.isNone);
Ember.empty = Ember.deprecateFunc("Ember.empty is deprecated. Please use Ember.isEmpty instead.", Ember.isEmpty) ;
```