More dynamic App::set()

[metawort]

I really like your framework, but I stumbled upon the rather redundant code of App::set(). I'd suggest to use something like this instead:

public function set($key, $value) {
    $keys = explode('/',$key);

    if (count($keys)>5) return false;

    $registry =& $this->registry;

    foreach ($keys as $key) {
        $registry =& $registry[$key];
    }

    $registry = $value;

    return $this;
}

That way you also won't have to limit the number of keys (but I kept the limit in case you had good reasons for it ^^).