HDFS-7387. NFS may only do partial commit due to a race between COMMIT and write. Contributed by Brandon Li

(cherry picked from commit 99d9d0c2d19b9f161b765947f3fb64619ea58090)

Conflicts:
	hadoop-hdfs-project/hadoop-hdfs-nfs/src/main/java/org/apache/hadoop/hdfs/nfs/nfs3/OpenFileCtx.java
YARN-570. Time strings are formated in different timezone. (Akira Ajisaka and Peng Zhang via kasha)

(cherry picked from commit 840b13110d63d7e062cefd4b993cc7dea44aed8d)
HDFS-7389. Named user ACL cannot stop the user from accessing the FS entity. Contributed by Vinayakumar B.

(cherry picked from commit 163bb55067bde71246b4030a08256ba9a8182dc8)
HDFS-7375. Move FSClusterStats to o.a.h.h.hdfs.server.blockmanagement. Contributed by Haohui Mai.