Merge remote-tracking branch 'apache/master' into driver-test

conf/log4j.properties.template

...main/resources/org/apache/spark/log4j-defaults.properties

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

.../main/scala/org/apache/spark/api/java/JavaDoubleRDD.scala

...rc/main/scala/org/apache/spark/api/java/JavaPairRDD.scala

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

...rc/main/scala/org/apache/spark/api/java/JavaRDDLike.scala

...in/scala/org/apache/spark/api/java/JavaSparkContext.scala

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

...main/scala/org/apache/spark/broadcast/HttpBroadcast.scala

...n/scala/org/apache/spark/broadcast/TorrentBroadcast.scala

...rc/main/scala/org/apache/spark/deploy/master/Master.scala

...rc/main/scala/org/apache/spark/deploy/worker/Worker.scala

...src/main/scala/org/apache/spark/io/CompressionCodec.scala

...in/scala/org/apache/spark/network/ConnectionManager.scala

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

core/src/main/scala/org/apache/spark/rdd/CheckpointRDD.scala