APIDOC-11 Infinite nesting

Example
```ruby
  parameter :test, 'test', required: true, scope: { auth: { user: { deeep: { too_deep: :test } } } }, type: 'string', paramType: 'form'
```

```json
{
  required: true,
  scope: "auth[user][deeep][too_deep]",
  type: "string",
  paramType: "form",
  name: "test",
  description: "test"
}
```

```
Started POST "/v1/users" for 127.0.0.1 at 2014-10-25 01:28:38 +0300
Processing by Api::V1::UsersController#create as JSON
  Parameters: {"user"=>{"first_name"=>"test", "last_name"=>"test", "email"=>"test@test.com", "password"=>"[FILTERED]"}, "auth"=>{"user"=>{"deeep"=>{"too_deep"=>{"test"=>"yay"}}}}}
```

![screenshot 2014-10-25 01 32 17](https://cloud.githubusercontent.com/assets/154947/4777311/b5db86ec-5bcd-11e4-9b91-7f1099d304b5.png)