Enqueues the default ThickBox js and css.

If any of the settings need to be changed, this can be done with another js
file similar to media-upload.js. That file should
require array(‘thickbox’) to ensure it is loaded after.

function add_thickbox() {
	wp_enqueue_script( 'thickbox' );
	wp_enqueue_style( 'thickbox' );

	if ( is_network_admin() ) {
		add_action( 'admin_head', '_thickbox_path_admin_subfolder' );
	}
}