ALTER TABLE `xf_conversation_message`
ADD COLUMN `edit_count` int unsigned not null default 0,
ADD COLUMN `last_edit_date` int unsigned not null default 0,
ADD COLUMN `last_edit_user_id` int unsigned not null default 0;
ALTER TABLE `xf_conversation_master`
ADD COLUMN `edit_count` int unsigned not null default 0,
ADD COLUMN `last_edit_date` int unsigned not null default 0,
ADD COLUMN `last_edit_user_id` int unsigned not null default 0;