Merge remote branch 'upstream/master' into enhance_pipe

core/src/main/java/spark/network/netty/FileServer.java

core/src/main/scala/spark/PairRDDFunctions.scala

core/src/main/scala/spark/RDD.scala

core/src/main/scala/spark/SequenceFileRDDFunctions.scala

core/src/main/scala/spark/Utils.scala

core/src/main/scala/spark/api/java/JavaPairRDD.scala

core/src/main/scala/spark/api/java/JavaRDD.scala

core/src/main/scala/spark/api/java/JavaRDDLike.scala

core/src/main/scala/spark/rdd/CoGroupedRDD.scala

...n/scala/spark/scheduler/cluster/SchedulingAlgorithm.scala

core/src/main/scala/spark/storage/BlockFetcherIterator.scala

core/src/main/scala/spark/storage/BlockManager.scala

core/src/main/scala/spark/storage/BlockManagerMaster.scala

...rc/main/scala/spark/storage/BlockManagerMasterActor.scala

core/src/main/scala/spark/storage/BlockManagerMessages.scala

...src/main/scala/spark/storage/BlockManagerSlaveActor.scala

core/src/main/scala/spark/storage/BlockManagerWorker.scala

core/src/main/scala/spark/storage/DiskStore.scala

core/src/main/scala/spark/storage/StorageUtils.scala

core/src/main/scala/spark/util/AkkaUtils.scala