HBASE-9020 Make hbase-it HBASE_HOME configurable

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1506205 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9008 Reenable TestReplicationKillSlaveRS.killOneSlaveRS

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1506245 13f79535-47bb-0310-9956-ffa450edef68