Fixed embedded belongsTo relationships

[marcoow]

This fixes an an error where the code

Person = DS.Model.extend({
  name: DS.attr('string')
});
Group = DS.Model.extend({
  name: DS.attr('string'),
  people: DS.hasMany(Person)
});
Person.reopen({
  group: DS.belongsTo(Group)
});
Adapter.map(Person, {
  group: { embedded: 'always' }
});

store.createRecord(Person, { name: "Tom Dale", group: store.createRecord(Group, { name: "Ember.js Group" }) });
store.commit();

would trigger 2 POST requests (1 to /people, 1 to /groups) where you would only expect 1 (because of group being embedded in person).

[wagenet]

@marcoow Can you squash these commits and rebase on master? Thanks!

[marcoow]

@wagenet: done

[wycats]

Embedded relationships aren't back in Ember Data 1.0 Beta yet. When it comes back, I'll make sure to consider this case.