Add Composer.json and namespaces to the classes

[rvanlaak]

Please take a look at the attached code. I've added a composer file, which makes it possible to place the library on Packagist.

Aside of that, I also separated all classes and made one file per class. At top of the classes there now is a namespace.

Most of the code styling has been optimized for psr-0. None of the functions itself has been changed, this just makes it better maintainable.

[rvanlaak]

The next thing in my opinion should be #40 , so that is what I'm going to think about next.

Before I start with the Symfony2 bundle, I would like to add an autoloader for the old users, so they can keep making use of the code identically as they did before. I've added TODO's to the original "tropo-rest.class.php" and "tropo.class.php" file.

[rvanlaak]

In the latest commits I've fixed the use statements, so the last BC break should be an incorrect functioning autoloader.