Security accounts

Implemented a mechanism that makes normal accounts be valid under a supervision track. A valid supervisor is required to keep the account valid. New features:

• each user has a profile
• the registration step asks for a valid godfather
• daily cron actions clean invalid users and check for account validity
• each user need to validate his account every year
• a supervision track give the possibility to track which account is supervised by which user (history is kept)
• a supervisor can reject a supervisee at anytime
• acceptance and rejection messages are emailed to users
• a new supervisor request can be made by supervisee at anytime and an email is sent to inform the supervisor
• if the year validation is not performed the account gets blocked after a specific deadline (account re-activation possible)
• implemented account management for supervisees
• implemented supervisee management for supervisors
• implemented unittest with the API

Note: Must take into accounts that supervisor registration and account tracking is not implemented yet.