Working out outdated migrations

Several migrations were failing when running db:migrate at the initial release version from an empty database.
These changes took out statements that were causing migrations to fail, usually because of references to models that no longer exist.

db/migrate/20120809201855_migrate_bookmarks_to_post_actions.rb

@@ -1,9 +1,5 @@
 class MigrateBookmarksToPostActions < ActiveRecord::Migration
   def up
-    execute "insert into post_actions(user_id, post_action_type_id, post_id, created_at, updated_at)
-    select distinct b.user_id, #{PostActionType.bookmark.id} , p.id, b.created_at, b.updated_at 
-from bookmarks b
-join posts p on p.forum_thread_id = b.forum_thread_id and p.post_number = b.post_number"
     drop_table "bookmarks"
   end