[#25,model][xs]: remove artificial field attribute (follow up to penultimate commit cf42e43ff0f32ba24e940455b060ae278025942b).

src/model.js

@@ -97,6 +97,7 @@ my.Field = Backbone.Model.extend({
     // if a hash not passed in the first argument is set as value for key 0
     if ('0' in data) {
       this.set({id: data['0']});
+      this.unset('0');
     }
     if (this.attributes.label == null) {
       this.set({label: this.id});

test/model.test.js

@@ -16,6 +16,7 @@ test('Field: basics', function () {
   var field = new recline.Model.Field('x');
   equal(field.id, 'x', 'Set of id from single argumentst to ctor');
   equal(field.attributes.id, 'x', 'Set of id from single argumentst to ctor');
+  ok(!('0' in field.toJSON()), 'Should have removed artificially created 0 key in attributes');
 });
 
 })(this.jQuery);