1. Add a timestamp for comment editing/deletion and an ID of the last user
who edited a comment:

----
ALTER TABLE PackageComments
	ADD COLUMN EditedTS BIGINT UNSIGNED NULL DEFAULT NULL,
	ADD COLUMN EditedUsersID INTEGER UNSIGNED NULL DEFAULT NULL,
	ADD FOREIGN KEY (EditedUsersID) REFERENCES Users(ID) ON DELETE SET NULL;
----

2. Add fields to store the ID and comment of the last user who flagged a
package out-of-date:

----
ALTER TABLE PackageBases
	ADD COLUMN FlaggerUID INTEGER UNSIGNED NULL DEFAULT NULL,
	ADD COLUMN FlaggerComment VARCHAR(255) NOT NULL,
	ADD FOREIGN KEY (FlaggerUID) REFERENCES Users(ID) ON DELETE SET NULL;
----

3. Add field to store the state of a user's email address:

----
ALTER TABLE Users
	ADD COLUMN HideEmail TINYINT UNSIGNED NOT NULL DEFAULT 0;
----