Open Symfony 3 compatibility
Open Symfony 3 compatibility

Closes #668

sonata-project/SonataPageBundle,Th3Mouk/SonataPageBundle,Dunduro/SonataPageBundle,sonata-project/SonataPageBundle,Dunduro/SonataPageBundle,Th3Mouk/SonataPageBundle,Dunduro/SonataPageBundle,Dunduro/SonataPageBundle,Dunduro/SonataPageBundle,Th3Mouk/SonataPageBundle,Th3Mouk/SonataPageBundle