Fail with a nice error message when attempting to use a maven deployer to resolve dependencies.
Added PublicationAwareRepository to represent a repository that knows how to publish stuff. This allows us to distinguish between converting a repository definition to a DependencyResolver to expose via the DSL for backwards compatiblity purposes, and converting a repository definition to something that can publish. This also allows different types to be used in the DSL and for publishing (we don't make use of this yet).