Basic composer packaging with PSR0 style namespacing and autoloading

Hey Chris,

I added a composer.json file to help integrate boris better into projects using the composer packaging system. It'd be great to get boris into https://packagist.org/.

Unfortunately, this meant I had to change the class/namespacing style to make boris fit the PSR0 style.

I added a `lib/boris.php` file for folks that don't want to use composer's autoloading. It will mean boris continues to work out of the box without having to `composer install` all the time.

Let me know what you think. Cheers! :-)