Merge pull request #847 from rxin/rdd

core/src/main/scala/spark/Aggregator.scala

core/src/main/scala/spark/BlockStoreShuffleFetcher.scala

core/src/main/scala/spark/Dependency.scala

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

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

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

core/src/main/scala/spark/ShuffleFetcher.scala

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

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

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

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

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

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

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

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

core/src/main/scala/spark/scheduler/ShuffleMapTask.scala

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

core/src/test/scala/spark/CheckpointSuite.scala

core/src/test/scala/spark/PairRDDFunctionsSuite.scala

core/src/test/scala/spark/RDDSuite.scala