[HttpFoundation] JsonResponse::setEncodingOptions accepts also integer

Now you can set encoding options like:
```
$response->setEncodingOptions(JSON_UNESCAPED_UNICODE | $response->getEncodingOptions());
feature #9963 [HttpFoundation] JsonResponse::setEncodingOptions accepts also integer (stloyd)

This PR was merged into the 2.5-dev branch.

Discussion
----------

[HttpFoundation] JsonResponse::setEncodingOptions accepts also integer

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Tests pass?   | yes
| License       | MIT

Now you can also set encoding options like:
```php
$response->setEncodingOptions(JSON_UNESCAPED_UNICODE | $response->getEncodingOptions());

Commits
-------

f8bc3b2 [HttpFoundation] JsonResponse::setEncodingOptions accepts also integer