HBASE-8553. improve unit-test coverage of package org.apache.hadoop.hbase.mapreduce.hadoopbackport. Contributed by Ivan A. Veselovsky.

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1536502 13f79535-47bb-0310-9956-ffa450edef68
HBASE-9851 TestHBaseFsck.testQuarantineMissingHFile is flaky

git-svn-id: https://svn.apache.org/repos/asf/hbase/branches/0.94@1536510 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/0.94' into 0.94-gd
Merge remote branch 'origin/0.94-gd' into fb-HBASE-8559-0.94-gd