Favorite "aside"-sections moved, also small fixes left from before

Action now has 'isAction' which compares the loaded Action with names
of classes in an array (added without the 'Action') to its own type.

plugins/SiteNoticeInSidebar/SiteNoticeInSidebarPlugin.php

@@ -60,7 +60,7 @@ class SiteNoticeInSidebarPlugin extends Plugin
         return false;
     }
 
-    function onStartShowSections($action)
+    function onStartShowSections(Action $action)
     {
         $text = common_config('site', 'notice');
         if (!empty($text)) {