HADOOP-10607. Create an API to separate credentials/password storage from 
applications. (Larry McCay via omalley)


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1611391 13f79535-47bb-0310-9956-ffa450edef68
HADOOP-10607 Forgot the CHANGES.txt.


git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1611393 13f79535-47bb-0310-9956-ffa450edef68