merge YARN-579 from trunk. Stop setting the Application Token in the AppMaster env, in favour of the copy present in the container token field. Contributed by Vinod Kumar Vavilapalli.


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merge MAPREDUCE-5181 from trunk. RMCommunicator should not use AMToken from the env. Contributed by Vinod Kumar Vavilapalli. 


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HDFS-4745. Merge 1475623 from trunk

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HADOOP-9357. Revert the change r1461901 to fix TestFcHdfsSymlink failures

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