Upgrade to symfony 2.6 compatible form extensions

[kralos]

As of symfony 2.6

public function configureOptions(OptionsResolver $resolver)
{
    $resolver->setDefined(array(/** 'option1', 'option2' */));
}

should be used instead of:

public function setDefaultOptions(OptionsResolverInterface $resolver)
{
    $resolver->setOptional(array(/** 'option1', 'option2' */));
}

As of 2.7 the former method is also deprecated

[althaus]

👍

[kralos]

Fixed #375

[althaus]

You missed to update the form types accordingly. I'll prepare a separate PR to fix this issue.

[althaus]

Sorry for the two commits here. Missed to tell the repo to not f*** up the lineendings at first. 🔨