Rewrite adding support for namespacing, UTMV cookie and unit testings.

Hey,

I'd been using your cookie parser for some time and decided to take it a couple of steps farther in terms of form and function.  Basically, I made a class for each cookie and a "Tracker" class to act as the universal interface to the data contained in the cookies.  I added support for the UTMV cookie and the CustomVars that it stores.  I also added PHPUnit tests.  You'll also notice, of course, that I put things in a namespacing scheme and included and autoloader.

I really appreciate the work you put in here and hope you will like the changes I've implemented.  I think this would be a useful component for a variety of web analytics projects/dashboards in PHP.  I could see this bundled in a Wordpress plugin as well and if you're interested, it's a side project I'd be interested in pursuing.

All my best,

Roger Webb