Quotent (division)

```js
  var MyType = Ember.Object.extend({
    c: EmberCPM.Macros.quotient('a', 'b'),
    d: EmberCPM.Macros.quotient('a', 3),
    e: EmberCPM.Macros.quotient(3, 'a'),
    f: EmberCPM.Macros.quotient(),
    g: EmberCPM.Macros.quotient('a'),
    h: EmberCPM.Macros.quotient(Ember.computed.alias('a'), 2)
  });

  var myObj = MyType.create({
    a: 6,
    b: 2
  });

```

Supersedes #19, supports composable macros
Don't you think that the former like is clearer?