HADOOP-10851: Merging r1617612 from trunk to branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1617613 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10962. Flags for posix_fadvise are not valid in some architectures (David Villegas via Colin Patrick McCabe)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1617622 13f79535-47bb-0310-9956-ffa450edef68
YARN-2399. FairScheduler: Merge AppSchedulable and FSSchedulerApp into FSAppAttempt. (kasha)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1617623 13f79535-47bb-0310-9956-ffa450edef68