[EAGLE-889] Add a restful API for Hadoop running queue to query top N users or jobs

https://issues.apache.org/jira/browse/EAGLE-889

Sample 1: query the top N users/jobs of memory usage under queue1 on site1 at time 1487156721356
http://localhost:9090/rest/queue/memory?top=10&queue=queue1&currentTime=1487156721356&site=site1

Sample 2: query the current queue hierarchy
http://localhost:9090/rest/entities?query=QueueMappingService[site=%22sandbox%22]{*}&pageSize=10000

Author: Zhao, Qingwen <qingwzhao@apache.org>

Closes #805 from qingwen220/EAGLE-889.
12 files changed