Added Namespace+Autoloading compatibility

Little piece of PHP to make Mobile_Detect auto-loadable in PSR-0 compatible PHP autoloaders like the Symfony Universal ClassLoader by Fabien Potencier. Since PSR-0 handles an underscore in classnames (on the filesystem) as a slash, "Mobile_Detect.php" autoloaders will try to convert the classname and path to "Mobile\Detect.php". This script will ensure autoloading with: