HDFS-5625. Write end user documentation for HDFS ACLs. Contributed by Chris Nauroth.

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HDFS-5625. Add documentation example for setting a default ACL. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-4685@1567422 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5925. ACL configuration flag must only reject ACL API calls, not ACLs present in fsimage or edits. Contributed by Chris Nauroth.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-4685@1567450 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5923. Do not persist the ACL bit in the FsPermission. Contributed by Haohui Mai.

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HDFS-5933. Optimize the FSImage layout for ACLs. Contributed by Haohui Mai.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/HDFS-4685@1567785 13f79535-47bb-0310-9956-ffa450edef68
HDFS-5932. Ls should display the ACL bit. Contributed by Chris Nauroth.

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