Allow the blocking of accounts to be linked to roles

Additional logic to have a list of roles to which the blocking of accounts affects, this will allow a site owner to block privileged accounts that have attempted brute force attacks against them, but does not block the accounts of normal everyday users which could have the same.

For example, you have std users that comment etc around the site, you do not want to block these users (lots of them) but you have editorial accounts (editor role) that you want to be more secure, so this module is idea for blocking them user accounts with the editor role if they are attacked.