* 3.4:
[Phpunit] fixed support for PHP 5.3
Response prepare method update
[Workflow] Added missing license header
Check if Client exists when test.client does not exist, to provide clearer exception message
[Form] Preventing validation of children if parent with Valid constraint has no validation groups
[Tests] fixed compatbility of assertEquals(): void
[Intl] Fix test
[Validator] Add the missing translations for the Arabic (ar) locale
[Intl] Add compile binary
[Form] Fixed some phpdocs
* ScalarMarkingStore -> SingleStateMarkingStore
* PropertyAccessorMarkingStore -> MultipleStateMarkingStore
And I also made optionnal the `marking_store` config, to let the
componant choose the best marking store depending on the type
(state_machine or workflow).
