title: Marking ember-data records as existing
body: <p>I have a somewhat unique circumstance where I wrote a caching layer for ember-data that serializes records to localstorage. When I deserialize my cache into the ember-data models I use <code>this.store.createRecord('model_name', cacheData);</code>. These records I am caching have existing values on the server. This works for me fine up until I want to <code>save()</code> the record. The save thinks the record is a new record even though it has an "id" attribute. When <code>save()</code> is called a POST is made to my application server instead of a PUT. Does anyone know a way to flag records in the store as not new.</p>