WIP [ticket/12066] Symfony Forms

[EXreaction]

http://tracker.phpbb.com/browse/PHPBB3-12066

Example Form:

$form = $phpbb_container->get('form')
    ->get_builder()
    ->setAction(append_sid($phpbb_root_path . 'test.' . $phpEx))
    ->add('author', 'text', array(
        'label'  => 'AUTHOR',
    ))
    ->add('email', 'email', array(
        'label'  => 'EMAIL_ADDRESS',
    ))
    ->add('number', 'number', array(
        'max_length' => 4
    ))
    ->add('dueDate', 'date', array(
        'widget' => 'single_text',
        'label'  => 'Due Date',
    ))
    ->add('submit', 'submit')
    ->getForm()
;

$phpbb_container->get('form')->handle_request($form, $request, $symfony_request);

if ($form->isValid())
{
    echo 'valid';
}

$template->set_filenames(array('test' => 'test.html'));

$template->assign_var('testform', $form->createView());

$template->display('test');

Template:

{{form(testform)}}

[imkingdavid]

This function is identical to trans() except the $count parameter. If the function is required by Symfony to exist we should probably at least reduce code duplication by just wrapping trans() like so:
return trans($message, $arguments, $domain, $locale);

[EXreaction]

Yes, I wasn't yet exactly sure if these work this way or have some differences yet.

[vinny]

2013

[michaelcullum]

https://github.com/symfony/symfony-marketing/blob/master/projects/phpbb.yml needs updating upon merging of this PR to include the new 3.