Incorrect path for dynamic build when App.baseUrl is set

I use the build in server in CakePHP 2.3. Thus my <code>App.baseUrl</code> is <code>env('SCRIPT_NAME')</code>

AssetCompress helper would render this markup:

```html
<link rel="stylesheet" type="text/css" href="/cache_css/default.css" />
```
Which is incorrect and simply 404.

This patch wraps the helpers <code>$baseUrl</code> to bring out the <code>App.baseUrl</code>. i.e.

```html
<link rel="stylesheet" type="text/css" href="/index.php/cache_css/default.css" />
```

I've also tested this patch in an environment with doesn't set <code>App.baseUrl</code>. So for a least in development, I cannot see any issues.