Improve library for PSR-4 compatibility

PSR-4 is now stable and mature for use in libraries as well as being
part of the composer autoload handler. This now allows us to clean up
our libraries from the old PSR-0 structure and basically move into a
package based autoloader rather than the deprecated structure of PSR-0

For more information read:
http://seld.be/notes/psr-4-autoloading-support-in-composer
http://www.sitepoint.com/battle-autoloaders-psr-0-vs-psr-4/

@afoozle any chance you can give this a review for me :+1: