Create module::event() which runs Gallery events. It works by

convention.  To respond to the "photo_created" event in the gmaps
module, you create modules/gmaps/helpers/gmaps_event.php containing
class gmaps_event which has function photo_created.

Renamed all events from gallery.foo.bar to foo_bar
Updated tag module to use new convention.

modules/comment/helpers/comment.php

@@ -52,7 +52,7 @@ class comment_Core {
     $comment->item_id = $item_id;
 
     $comment->save();
-    Event::run("gallery.comment.created", $comment);
+    module::event("comment_created", $comment);
 
     return $comment;
   }