def user_keypairname(user=nil)
      user ||= current_machine_user
      path = defined_keypairpath user
      if path
        Huxtable.keypair_path_to_name(path)
      else
        n = current_user_is_root?(user) ? '' : "-#{user}"
        "key-%s-%s%s" % [@@global.zone, current_machine_group, n]
      end    
    end
def user_keypairname(user=nil)
      user ||= current_machine_user
      path = defined_keypairpath user
      if path
        Huxtable.keypair_path_to_name(path)
      else
        n = current_user_is_root?(user) ? '' : "-#{user}"
        "key-%s-%s%s" % [@@global.zone, current_machine_group, n]
      end    
    end
Returns the name of the current keypair for the given user.
 If there's a private key path in the config this will return
 the basename (it's assumed the Amazon Keypair has the same
 name as the file). Otherwise this returns the Rudy style
 name: <tt>key-ZONE-ENV-ROLE-USER</tt>. Or if this the user is
 root: <tt>key-ZONE-ENV-ROLE</tt>