$autoload['libraries'] = array('config_loader');

defined('BASEPATH') OR exit('No direct script access allowed.');

class Config_loader
{
    protected $CI;

    public function __construct()
    {
        $this->CI =& get_instance(); //read manual: create libraries

        $dataX = array(); // set here all your vars to views

        $dataX['titlePage'] = 'my app title';
        $dataX['urlAssets'] = base_url().'assets/';
        $dataX['urlBootstrap'] = $dataX['urlAssets'].'bootstrap-3.3.5-dist/';

        $this->CI->load->vars($dataX);
    }
}

<title><?php echo $titlePage; ?></title>
<!-- Bootstrap core CSS -->
<link href="<?php echo $urlBootstrap; ?>css/bootstrap.min.css" rel="stylesheet">
<!-- Bootstrap theme -->
<link href="<?php echo $urlBootstrap; ?>css/bootstrap-theme.min.css" rel="stylesheet">