www restriction ignored

It would be nice to have an option like "set www subdomain as default".
I needed to make www.example.com the default url, instead of example.com.

In order to do this, I've modified the subdomain module at the row 407:

  else {
    $options['base_url'] = 'http://www.'. subdomain_base_domain();
  }

And I've modified the functions custom_url_rewrite_inbound and custom_url_rewrite_outbound in my settings.php in this way:

function custom_url_rewrite_outbound(&$path, &$options, $original_path) {
  // Used by the Subdomain module to generate URLs with subdomains
  if (module_exists('subdomain') and arg(0,$path)!='views') {
    subdomain_url_rewrite_outbound($path, $options);
  }
}

function custom_url_rewrite_inbound(&$result, $path, $path_language) {
  // Used by the Subdomain module to correctly interpret URLs with subdomains
  if (module_exists('subdomain') and arg(0,$path)!='views' and 
substr($_SERVER['HTTP_HOST'],0,3)!='www') {
    subdomain_url_rewrite_inbound($result, $path, $path_language);
  }
}  

The "views" part is a fix to an issue related to the views module ajax pager not working in subdomain pages.