Fix error when using Symfony annotations on controller action

[jdecool]

When using the mailer, the template render attributes property of the Request. This property can contain object if we use some annotation of the SensionExtraFrameworkBundle which cause an exception on template rendering.

Example :

/**
 * @Route("/", name="homepage")
 * @Method({"GET", "POST"})
 */
public function indexAction(Request $request)
{
    return $this->render('default/index.html.twig', [
        'base_dir' => realpath($this->getParameter('kernel.root_dir').'/..'),
    ]);
}

This PR is for fixing that issue. It introduce a MailerTransform to convert each properties to an array or a scalar value.

[mhor]

LGTM, ping @NoiseByNorthwest

[jdecool]

Hey, some news about this PR ?

It fix an error we currently have in production.

Thanks.

[mhor]

Thanks @jdecool . released as 1.2.3 . Sorry for late reply/merge

[jdecool]

Great ! Thank you.

A small contribution for a bundle we use in our production apps :)