HADOOP-9307. BufferedFSInputStream.read returns wrong results after certain seeks. Contributed by Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1482378 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9560. Merge change 1482372 from trunk.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1482380 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-9220. Unnecessary transition to standby in ActiveStandbyElector. Contributed by Tom White and Todd Lipcon.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1482402 13f79535-47bb-0310-9956-ffa450edef68
Merge remote branch 'origin/branch-2' into branch-2-gd
Merge remote branch 'origin/branch-2-gd' into fb-MAPREDUCE-4884-branch-2-gd