Merge remote-tracking branch 'upstream/master' into ui_new_state

...ava/org/apache/spark/network/netty/FileServerHandler.java

...ain/java/org/apache/spark/network/netty/PathResolver.java

...cala/org/apache/hadoop/mapred/SparkHadoopMapRedUtil.scala

...rg/apache/hadoop/mapreduce/SparkHadoopMapReduceUtil.scala

core/src/main/scala/org/apache/spark/MapOutputTracker.scala

core/src/main/scala/org/apache/spark/SparkContext.scala

core/src/main/scala/org/apache/spark/SparkEnv.scala

core/src/main/scala/org/apache/spark/SparkHadoopWriter.scala

...apache/spark/api/java/function/DoubleFlatMapFunction.java

...la/org/apache/spark/api/java/function/DoubleFunction.java

.../org/apache/spark/api/java/function/FlatMapFunction.scala

...org/apache/spark/api/java/function/FlatMapFunction2.scala

...in/scala/org/apache/spark/api/java/function/Function.java

...n/scala/org/apache/spark/api/java/function/Function2.java

...g/apache/spark/api/java/function/PairFlatMapFunction.java

...cala/org/apache/spark/api/java/function/PairFunction.java

...rc/main/scala/org/apache/spark/api/python/PythonRDD.scala

.../main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala

.../scala/org/apache/spark/network/netty/ShuffleSender.scala

.../main/scala/org/apache/spark/scheduler/DAGScheduler.scala