[aphrodite] Invitation class
[aphrodite] Rename mailer
[aphrodite] Add before filter action
[aphrodite] Rename mailer
[aphrodite] Add invitations controller
[aphrodite] Remove odd whitespace
[aphrodite] Fix missing constant
[aphrodite] Add require invitation link
[aphrodite] Add burn! as a class method
[aphrodite] Registrations controller
[aphrodite] Add invitation token validation
[aphrodite] Add flash messages
[aphrodite] Add invitation token to registration process