Allow set Form::setPreferFormInputFilter via options

[thestanislav]

Allow set setPreferFormInputFilter options while building forms by FormFactory using form spec.

[Ocramius]

@thestanislav can you add simple coverage for this one?

[thestanislav]

This can be used to create forms via form factory

use Zend\Form\Factory;

$factory = new Factory();
$form    = $factory->createForm(array(
    'options' => array(
        'prefer_form_input_filter' => true
    ),
    'elements' => array(
        array(
            'spec' => array(
                'name' => 'name',
                'options' => array(
                    'label' => 'Your name',
                ),
                'type'  => 'Text',
            )
        ),
        array(
            'spec' => array(
                'type' => 'Zend\Form\Element\Email',
                'name' => 'email',
                'options' => array(
                    'label' => 'Your email address',
                )
            ),
        )
    ),
));

[weierophinney]

I added unit tests on merge.