title: Ember data 1.0.0: confused with per-type adapters and serializers
body: <p>I am migrating from Ember data 0.13 to 1.0.0 beta.  According to the doc <a href="https://github.com/emberjs/data/blob/master/TRANSITION.md">https://github.com/emberjs/data/blob/master/TRANSITION.md</a>, there are now per type adapters and per type serializers.</p>
  
  <p>This means that I can no longer define a "myRestAdapter" with some specific overrides for the primary key and the authentication. I need to implement this code now for each model type resulting in duplicating xx times the same code.</p>
  
  <p>Code in Ember data 0.13:</p>
  
  <pre><code>App.AuthenticatedRestAdapter = DS.RESTAdapter.extend({  
  
    serializer: DS.RESTSerializer.extend({
      primaryKey: function() {
        return '_id';
      }
    }),
  
    ajax: function (url, type, hash) {
      hash = hash || {};
      hash.headers = hash.headers || {};
      hash.headers['Authorization'] = App.Store.authToken;
      return this._super(url, type, hash);
    }
  });
  </code></pre>
  
  <p>Code in Ember data 1.0.0 (only for setting the primary key to _id instead of _id:</p>
  
  <pre><code>App.AuthorSerializer = DS.RESTSerializer.extend({
  
    normalize: function (type, property, hash) {
      // property will be "post" for the post and "comments" for the
      // comments (the name in the payload)
  
      // normalize the `_id`
      var json = { id: hash._id };
      delete hash._id;
  
      // normalize the underscored properties
      for (var prop in hash) {
        json[prop.camelize()] = hash[prop];
      }
  
      // delegate to any type-specific normalizations
      return this._super(type, property, json);
    }
  
  });
  </code></pre>
  
  <p>Have I understood it correct that I need to copy this same block now for every model that requires the _id as primary key ?  Is there no longer a way to specify this once for the whole application ?</p>