Cleaned up package structure for Composer

Changed coding style to PSR-2, added a namespace, changed the directory structure to be PSR-0 friendly, and added a composer.json file to make this package installable using Composer.

Alex send me your Packagist.com username and I'll add you as a package maintainer if you see fit to accept this pull request.

https://packagist.org/packages/php_pandora_api/php_pandora_api