New feature: New authentication method management

Fixed issue 08865: User not in LDAP or in WebServer can log again
New feature #9431: Create LDAP users taking email and full name from LDAP server

Dev: Users have new permissions: Use DB internal authentication, use LDAP authentication, use WS authentication
Dev: When creating a user, we can choose LDAP or internal authentication. This configuration can be changed later. For example, we can change an user from internal to LDAP or we can allow both authentication methods for specific users.
Dev: If we choose LDAP authentication method, full name and email address are taken from LDAP at creation time (user and/or admins can change them later).
Dev: User not allowed to use internal DB authentication is not allowed to reset their password using "forgotten password" functionality
Dev: User not allowed to use internal DB authentication doesn't receive any password in welcome email