Feature #4149 : user account validity

- modifying database structure around users
- modifying unit tests datasets around users
- modifying models and query mechanism around users
- adding columns into ST_User for next features
- deleted users are retrieved by their state and no more by access level
- changing the management of user accessLevel information
- removing some dead code
- centralizing/refactoring some code
- adding action menus to block or unblock users (administration)
- adding blocked user management around user log in
- adding blocked user management around WEB-Services
- adding blocked user management around user blocked whereas a session is alive
- formatting the jsp files at webapp root
- formatting userContent.jsp file
- adjusting some unit tests