Two hooks for DoctrineBundle to allow ContainerFilterCollection

Allows the DoctrineBundle to inject a ```ContainerFilterCollection``` that creates filters through dependency injection. See doctrine/DoctrineBundle#245.

Would prefer to inject the ```FilterCollection``` into the constructor of the em, but since they have a cyclic dependency I chose setter injection.
Argument 1 passed to Doctrine\ORM\Query\Filter\SQLFilter::__construct() must be an instance of Doctrine\ORM\EntityManager, instance of Mock_EntityManagerInterface_8c0ce16c given.