define a new IPredicateInfo to mirror IDeriverInfo

[mmerickel]

One annoyance with predicates right now is that their signature is val, config which doesn't make much sense. It's not particularly good practice to pass around the config. The only reason it's done right now is because the containment predicate needs to call config.maybe_dotted. That's it. It'd be much preferred to be something like info, val which could more closely mirror the new IViewDeriverInfo. We could then define an IPredicateInfo which contained the registry and package information without passing the raw config.

This would be a backward compatibility issue, unfortunately, so I'd save it for Pyramid 2.0.