YARN-2760. Remove 'experimental' from FairScheduler docs. (Harsh J via kasha)

(cherry picked from commit ade3727ecb092935dcc0f1291c1e6cf43d764a03)
YARN-2279. Add UTs to cover timeline server authentication. Contributed by Zhijie Shen
YARN-2758. Update TestApplicationHistoryClientService to use the new generic history store. Contributed by Zhijie Shen
YARN-2741. Made NM web UI serve logs on the drive other than C: on Windows. Contributed by Craig Welch.

(cherry picked from commit 8984e9b1774033e379b57da1bd30a5c81888c7a3)
HDFS-7291. Persist in-memory replicas with appropriate unbuffered copy API on POSIX and Windows. Contributed by Xiaoyu Yao.

(cherry picked from commit c6f04f391b54e57467b3ae5d0a95bd96e7feaa82)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

(cherry picked from commit c2790932bd01c0a8a7c32a38ea99ed47c0fe05f8)