Classes annotated X should reside in package Y

[piotrooo]

I think we now have all the missing pieces to introduce a new rule that checks whether certain classes are located in specific package.

Motivation:
Let's imagine someone have an entity annotated with @Entity called, for example, User. They need to ensure that the class is located in the com.example.*db.model package.

What do you think?

[mnhock]

Will be part of the next release, thanks!