HDFS-6635. Refactor encryption zone functionality into new EncryptionZoneManager class. (wang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/fs-encryption@1608657 13f79535-47bb-0310-9956-ffa450edef68
Move something down in CHANGES-fs-encryption.txt

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/fs-encryption@1608658 13f79535-47bb-0310-9956-ffa450edef68