Easier install/config via composer

In order to achieve this, we have to move relevant files to a new
directory named 'CakePHP'.  This is required because phpcodesniffer
assumes that a standard will be under its own directory.

Once installed, user will need to configure `installed_paths` config
in CodeSniffer.conf file under `vendor/squizlabs/php_codesniffer`, eg:

```php
$phpCodeSnifferConfig = array(
    'installed_paths' => '/home/rachman/.composer/vendor/cakephp/cakephp-codesniffer',
);
```

No symlink/copying needed.