[RFC] Integrate Workflow component

[wouterj]

Symfony 3.2 will introduce a Workflow component. I think it would be great if we can integrate this into the publish workflow (e.g. publishing only in specific states).

To keep 3.0 support, we either have to make this pwc opt-in using a config setting or have to implement a BC layer (which isn't hard, as we can always require the component from this bundle).

[dbu]

i agree we should support it. i think it can't replace our publish thing, e.g. the date based decision can not be replaced by a state machine. (our name publish "workflow" is kind of misleading, as in the end it is a voter that decides yes or no, not a full workflow) i would make it an optional dependency for now, only load a workflow voter if the user configured states for some of the classes. and fail if workflows is not available but configured.