merge -c 1510772 FIXES: HADOOP-9816.  RPC Sasl QOP is broken (daryn)


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HDFS-4905. Merging change r1510773 from trunk to branch-2.

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HADOOP-9832. [RPC v9] Add RPC header to client ping (daryn)


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MAPREDUCE-5399. Unnecessary Configuration instantiation in IFileInputStream slows down merge. (Stanislav Barton via Sandy Ryza)

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HADOOP-9817. FileSystem#globStatus and FileContext#globStatus need to work with symlinks. (Colin Patrick McCabe via Andrew Wang)



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