Milestone 2.2 - more semantic/modular folder structure

[nbish11]

Instead of a folder structure resembling something like this:

/Klein/AbstractResponse.php
/Klein/HttpStatus.php
/Klein/Request.php
/Klein/Response.php
/Klein/ResponseCookie.php

$request = new Klein\Request;

Maybe, something like this could be done instead:

/Klein/Http/AbstractResponse.php
/Klein/Http/Status.php
/Klein/Http/Request.php
/Klein/Http/Response.php
/Klein/Http/Cookie.php

$request = new Klein\Http\Request;