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
hbase-9002: TestDistributedLogSplitting.testRecoveredEdits fails

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1506267 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/trunk' into trunk-gd
Merge remote branch 'origin/trunk-gd' into fb-HBASE-8559-trunk-gd