List licenses of all transitive dependencies for each package

If you are considering licenses, you most likely are not only interested in the license for the contents of a particular package, but also for those of its dependencies.

(and because there may be non-haskell/hackage dependencies: it would also make sense to add some new field to packages that describes the licenses of dependencies. e.g. in case you depend on some non-haskell library under a specific license. i guess a different tracker corresponds to that idea, though..)