v.2.1.3

* Added action: `send_user_authentication`; Notification informations as parameters
* Enhancement: `confirm-user-registration-notification-header` filter has user as arguement
* Enhancement: `confirm-user-registration-notification-subject` filter has user as arguement
* Enhancement: `confirm-user-registration-notification-message` filter has user as arguement

Signed-off-by: Ralf Hortt <me@horttcore.de>