HBASE-8954 TestSplitLogWorker#testPreemptTask failed

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1503512 13f79535-47bb-0310-9956-ffa450edef68
HBASE-8935 IntegrationTestBigLinkedList fails under load on 0.94 due to some scan issues - add logging

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1503524 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