User registration

• New users can register into the system using a registration link generated by the system administrators using the user email address. This email address will be the user identifier in the system
• On the registration page, the user should introduce its profile info.
  • The email address in the profile must be the same one used for generating the registration link
  • The user role selected in the profile will determine if the user is registered as a PaaS user (activity creator) or as a SaaS user (follower)