HBASE-10316 Canary#RegionServerMonitor#monitorRegionServers() should close the scanner returned by table.getScanner()



git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1558137 13f79535-47bb-0310-9956-ffa450edef68
HBASE-10294 ServerManager#onlineServers synchronization



git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1558174 13f79535-47bb-0310-9956-ffa450edef68