href attribute for associations was generated incorrectly

When using url-mode (baseUrl is defined), the href attribute is generated incorrectly:

```JSON
{
  "posts": [ ... ],
  "links": {
    "posts.comments": {
      "href": "http://example.com/post/{posts.comments}",
      "type": "comments"
    }
  }
}
```
Whereas the comments resource would be at http://example.com/comments/:id