HDFS-5849. Removing ACL from an inode fails if it has only a default ACL. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-4685@1563205 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10270. getfacl does not display effective permissions of masked. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-4685@1563219 13f79535-47bb-0310-9956-ffa450edef68
Merge branch 'HDFS-4685' into HDFS-5614
HDFS-5614: remove unnecessary test assertion.
HDFS-5614: generalize the mechanism for preserving specific inode features in snapshot copies.