Changed ember models to use moment for dates

Closes #2888

-Added moment-date `DS.Transform`
-`models/post` and `models/user` both use `DS.attr('moment-date')` in
place of `date` now.

core/client/models/post.js

@@ -12,11 +12,11 @@ var Post = DS.Model.extend({
     meta_title: DS.attr('string'),
     meta_description: DS.attr('string'),
     author: DS.belongsTo('user',  { async: true }),
-    created_at: DS.attr('date'),
+    created_at: DS.attr('moment-date'),
     created_by: DS.belongsTo('user', { async: true }),
-    updated_at: DS.attr('date'),
+    updated_at: DS.attr('moment-date'),
     updated_by: DS.belongsTo('user', { async: true }),
-    published_at: DS.attr('date'),
+    published_at: DS.attr('moment-date'),
     published_by: DS.belongsTo('user', { async: true }),
     tags: DS.hasMany('tag', { async: true }),
 

core/client/models/user.js

@@ -14,10 +14,10 @@ var User = DS.Model.extend({
     language: DS.attr('string'),
     meta_title: DS.attr('string'),
     meta_description: DS.attr('string'),
-    last_login: DS.attr('date'),
-    created_at: DS.attr('date'),
+    last_login: DS.attr('moment-date'),
+    created_at: DS.attr('moment-date'),
     created_by: DS.attr('number'),
-    updated_at: DS.attr('date'),
+    updated_at: DS.attr('moment-date'),
     updated_by: DS.attr('number'),
 
     isSignedIn: Ember.computed.bool('id'),

core/client/transforms/moment-date.js

@@ -0,0 +1,16 @@
+/* global moment */
+var MomentDate = DS.Transform.extend({
+    deserialize: function (serialized) {
+        if (serialized) {
+            return moment(serialized);
+        }
+        return serialized;
+    },
+    serialize: function (deserialized) {
+        if (deserialized) {
+            return moment(deserialized).toDate();
+        }
+        return deserialized;
+    }
+});
+export default MomentDate;