Merge branch 'master' of https://github.com/apache/incubator-spark into sbt-assembly-deps

assembly/README

assembly/pom.xml

bagel/pom.xml

bin/stop-slaves.sh

conf/fairscheduler.xml.template

conf/metrics.properties.template

core/pom.xml

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

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

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

...ain/scala/org/apache/spark/BlockStoreShuffleFetcher.scala

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

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

...c/main/scala/org/apache/spark/InterruptibleIterator.scala

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

core/src/main/scala/org/apache/spark/ShuffleFetcher.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/TaskContext.scala

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