kijiproject.github.com: SCORE-177. Support attaching a Freshener to a map-type family

issue: https://jira.kiji.org/browse/SCORE-177
review: https://review.kiji.org/r/1831
commit: https://github.com/kijiproject/kijiproject.github.com/commit/2f1c688e68be0d1ece362ce94e11838923827f1d