called before.
$user: The User for which the options have been saved
+'UserSendConfirmationMail': Called just before a confirmation email is sent to
+a user. Hook handlers can modify the email that will be sent.
+$user: The User for which the confirmation email is going to be sent
+&$mail: Associative array describing the email, with the following keys:
+ - subject: Subject line of the email
+ - body: Email body. Can be a string, or an array with keys 'text' and 'html'
+ - from: User object, or null meaning $wgPasswordSender will be used
+ - replyTo: MailAddress object or null
+$info: Associative array with additional information:
+ - type: 'created' if the user's account was just created; 'set' if the user
+ set an email address when they previously didn't have one; 'changed' if
+ the user had an email address and changed it
+ - ip: The IP address from which the user set/changed their email address
+ - confirmURL: URL the user should visit to confirm their email
+ - invalidateURL: URL the user should visit to invalidate confirmURL
+ - expiration: time and date when confirmURL expires
+
'UserSetCookies': DEPRECATED since 1.27! If you're trying to replace core
session cookie handling, you want to create a subclass of
MediaWiki\Session\CookieSessionProvider instead. Otherwise, you can no longer