code: def user_packages(request, user):
      
      session = DBSession()
      owned = Package.by_owner(session, user)
      maintained = Package.by_maintainer(session, user)
      owned = [('Owner', p.name) for p in owned]
      maintained = [('Maintainer', p.name) for p in maintained]
      return owned + maintained
docs: Retrieve a list of [role_name, package_name] for a given username.
      Role is either 'Maintainer' or 'Owner'.