Move user API to primary document format

closes #2593

- added new format to user API methods
- changed all places where the user api was used
- updated tests and added more coverage
- little bit of cleanup in utils/api

ghost/admin/models/user.js

@@ -1,9 +1,28 @@
-/*global Ghost */
+/*global Ghost,Backbone */
 (function () {
     'use strict';
 
     Ghost.Models.User = Ghost.ProgressModel.extend({
-        url: Ghost.paths.apiRoot + '/users/me/'
+        url: Ghost.paths.apiRoot + '/users/me/',
+
+        parse: function (resp) {
+            // unwrap user from {users: [{...}]}
+            if (resp.users) {
+                resp = resp.users[0];
+            }
+
+            return resp;
+        },
+
+        sync: function (method, model, options) {
+            // wrap user in {users: [{...}]}
+            if (method === 'create' || method === 'update') {
+                options.data = JSON.stringify({users: [this.attributes]});
+                options.contentType = 'application/json';
+            }
+
+            return Backbone.Model.prototype.sync.apply(this, arguments);
+        }
     });
 
 //    Ghost.Collections.Users = Backbone.Collection.extend({