YARN-2065 AM cannot create new containers after restart

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HDFS-6612. MiniDFSNNTopology#simpleFederatedTopology(int) always hardcode nameservice ID. Contributed by Juan Yu.

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HDFS-6614. Merging change r1607447 from trunk to branch-2.

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HDFS-6604. The short-circuit cache doesn't correctly time out replicas that haven't been used in a while (cmccabe)

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YARN-2241. ZKRMStateStore: On startup, show nicer messages if znodes already exist. (Robert Kanter via kasha)

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