give actual warnings etc from logging in

[josh-griffin]

at the moment if you log in and it fails it will always say "wrong username or password" - maybe it's unlikely but other errors can occur and so it would be good to say those things rather than convincing the user their password is wrong!

[josh-griffin]

will require some changes on desktop to return when a user is blocked rather than enter wrong details (Or should we like.. just not tell them)

[mark-prins]

I'd like to add a 'blocked' message. There's security motivation in not letting on whether it is the username or password which is wrong as that gives information away. but blocked? surely that is helpful.