added parse_args_r() function to allow for label overwrites

by replacing wp_parse_args() with custom parse_args_r() function it is possible to changes labels for the CPT like:
```php
<?php
public function __construct() {

	// Register this cpt
	// First parameter should be an array with Singular, Plural, and Registered name
	parent::__construct(
		array( __( 'Actress', 'your-text-domain' ), __( 'Actresses', 'your-text-domain' ), 'film-actress' ),
		array(
			'supports' => array( 'title', 'editor', 'excerpt', 'thumbnail' ),
			'labels'   => array( 'all_items' => __( 'All My Actresses', 'your-text-domain' ), ),
		)
	);

}
```