tree 079b973a8f18c9e54e51d6461dd967ddd037e884
parent bff6d8f4fc8152bb1e392a050143dbe70f74fbe2
author Ayaka Koshibe <ayaka@onlab.us> 1427933169 -0700
committer Ray Milkey <ray@onlab.us> 1428094510 +0000

Leadership construct includes List of NodeIds to describe current
leader/backups (candidates) for a topic. This includes removing the RoleInfo in
LeadershipEvent, to deduplicate information.

RoleInfo is also made a bit saner with the Optional leader field.

part of: Device Mastership store on top of LeadershipService
Reference: ONOS-76

Change-Id: I957c4d79125873d5a7280f60231d26d2806ab27f