Comparación de contenido

• User must be logged
• User must have ROLE_ADMINISTRATIVE_USER

1. User requests to add a user
2. System returns user creation form
3. User add customer data:
   1. A user may have multiple roles but ROLE_USER cannot mixed with any other role. 
   2. If user is created with ROLE_USER and as initial user it will be marked as default contact person and cannot be modified)
   3. If user is created as default contact person, email and phone fields are mandatory.
4. If new user is marked as contact person for a customer, system may unmark previous contact person if it existed.
5. if new user is associated with a customerId, system adds customer linkage.
6. System saves user.
7. If email is defined, system sends a confirmation email.

System must reject user creation if username just exists.

System must reject user createion if role is ROLE_USER and customerId is not defined.