add meta tag for short story url

app/controllers/stories_controller.rb

@@ -97,6 +97,8 @@ class StoriesController < ApplicationController
       @page_title = "[Story removed]"
     end
 
+    @short_url = @story.short_id_url
+
     @comments = Comment.ordered_for_story_or_thread_for_user(@story.id, nil,
       @user ? @user.id : nil)
     @comment = Comment.new

app/views/layouts/application.html.erb

@@ -5,6 +5,10 @@
   <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
   <link rel="apple-touch-icon" href="/apple-touch-icon.png"/>
   <meta name="viewport" content="width=device-width, initial-scale=1">
+  <% if @short_url %>
+    <link rev="canonical" rel="self alternate shorter shorturl shortlink"
+      href="<%= @short_url %>" />
+  <% end %>
   <title><%= @page_title ? "#{@page_title} | Lobsters" : "Lobsters" %></title>
   <%= stylesheet_link_tag    "application", :media => "all" %>
   <%= javascript_include_tag "application" %>