Creates a Drupal Ajax 'changed' command.
This command instructs the client to mark each of the elements matched by the given selector as 'ajax-changed'.
This command is implemented by Drupal.ajax.prototype.commands.changed() defined in misc/ajax.js.
$selector: A jQuery selector string. If the command is a response to a request from an #ajax form element then this value can be NULL.
$asterisk: An optional CSS selector which must be inside $selector. If specified, an asterisk will be appended to the HTML inside the $asterisk selector.
An array suitable for use with the ajax_render() function.
function ajax_command_changed($selector, $asterisk = '') {
return array(
'command' => 'changed',
'selector' => $selector,
'asterisk' => $asterisk,
);
}