[Steven Zahm]

@ dominic

These can be added via a filter. Install the Code Snippets plugin, then add a new snippet with the following code:

add_filter( 'cn_languages_options', 'cnl_add_more_languages' );

function cnl_add_more_languages( $options ) {

    $options['slv'] = 'Slovenian';
    $options['ind'] = 'Indonesian';
    $options['fil'] = 'Filipino';

    return $options;
}

I just also added these to the supported languages, so they will be in the next update.