first commit for object auth,will take new_blog for experiment

vendor/built_in_modules/new_blog/app/models/post.rb

@@ -5,4 +5,5 @@ class Post
   field :body, :type => String
   embeds_many :comments
   validates_presence_of :title, :body
+  has_one :object_auth,as: :obj_authable,dependent: :delete
 end