Added optional option in refreshing after modifying association table
    
    The 'refresh_option' of association field takes string. This string has to
    correspond with field name on details page. In case that the field is present
    the value of the field is passed to command as option in following format:
    
    {fieldname: field_value}
    
    Part of: https://fedorahosted.org/freeipa/ticket/5426
    
    Reviewed-By: Martin Basti <mbasti@redhat.com>
    Reviewed-By: Petr Vobornik <pvoborni@redhat.com>