Improving redirections and minifier.

- Minor changes in the minifier library.
- Updated mnfr.php with caching capacities.
- Updated mnfr.php with 404 exception when one of the input files doesn't exist.
- Fixed the mnfr.php bug that doesn't take the route with each file.
- Added relative URL support to the url.php / site_url() function.
- Now, if a controller doesn't allow parameters, when insert one MVCious returns a 404 error.
- Added an optional extension to the URL route. It's only necessary to uncomment the $config['controller_extension'] in config.php.