Safer sign-in to your admin

Safer sign-in to your admin. New passwords must be at least 10 characters - when you change it in My profile and when you set a password from an email link. Your current password keeps working until you change it. If you don't open the admin for 24 hours you are signed out automatically, and 7 days after signing in you sign in again with your password. The protection against password guessing now also stops attempts that change their address on every request.