kiji-rest: REST-48. Adds start_eid/end_eid and removes start_rk/end_rk.

review: https://review.kiji.org/r/1275
issue: https://jira.kiji.org/REST-48
commit: https://github.com/kijiproject/kiji-rest/commit/66bb482f30dc68176a48c90be99fa9f34889e0e0