YARN-1491. Upgrade JUnit3 TestCase to JUnit 4 (Chen He via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1550208 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10087. UserGroupInformation.getGroupNames() fails to return primary group first when JniBasedUnixGroupsMappingWithFallback is used (cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1550230 13f79535-47bb-0310-9956-ffa450edef68
YARN-408. Change CapacityScheduler to not disable delay-scheduling by default. Contributed by Mayank Bansal.
svn merge --ignore-ancestry -c 1550245 ../../trunk/


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1550246 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5023. TestSnapshotPathINodes.testAllowSnapshot is failing with jdk7 (Mit Desai via jeagles)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1550266 13f79535-47bb-0310-9956-ffa450edef68
HDFS-4201. NPE in BPServiceActor#sendHeartBeat (jxiang via cmccabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1550268 13f79535-47bb-0310-9956-ffa450edef68