Merge branch 'master' of github.com:apache/incubator-spark into kill

bin/stop-slaves.sh

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

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

...rc/main/scala/org/apache/spark/deploy/DeployMessage.scala

...n/scala/org/apache/spark/deploy/ExecutorDescription.scala

...in/scala/org/apache/spark/deploy/FaultToleranceTest.scala

...src/main/scala/org/apache/spark/deploy/JsonProtocol.scala

...ain/scala/org/apache/spark/deploy/LocalSparkCluster.scala

...rc/main/scala/org/apache/spark/deploy/client/Client.scala

...scala/org/apache/spark/deploy/client/ClientListener.scala

...ain/scala/org/apache/spark/deploy/client/TestClient.scala

...cala/org/apache/spark/deploy/master/ApplicationInfo.scala

...ala/org/apache/spark/deploy/master/ApplicationState.scala

...n/scala/org/apache/spark/deploy/master/ExecutorInfo.scala

...che/spark/deploy/master/FileSystemPersistenceEngine.scala

.../org/apache/spark/deploy/master/LeaderElectionAgent.scala

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

...scala/org/apache/spark/deploy/master/MasterMessages.scala

...la/org/apache/spark/deploy/master/PersistenceEngine.scala

.../scala/org/apache/spark/deploy/master/RecoveryState.scala