added lock to private posts on show pages

public/javascripts/app/templates/post-viewer/author.handlebars

@@ -18,5 +18,8 @@
 
   <div class="post-time">
     <time datetime="{{created_at}}" />
+    {{#unless public}}
+      <i class="icon-lock"> </i>
+    {{/unless}}
   </div>
 </div>

public/javascripts/app/views/post-viewer/feedback.js

@@ -32,6 +32,7 @@ app.views.PostViewerFeedback = app.views.Feedback.extend({
   hidePane : function(evt){ this.trigger("hidePane") },
 
   requireAuth : function(evt) {
+    if( app.currentUser.authenticated() ) { return }
     alert("you must be logged in to do that!")
     return false;
   }