Merge branch 'master' of github.com:mesos/spark into spark-633

bin/start-all.sh

bin/start-master.sh

bin/start-slave.sh

core/src/main/scala/spark/executor/Executor.scala

core/src/main/scala/spark/executor/ExecutorExitCode.scala

...main/scala/spark/scheduler/cluster/ClusterScheduler.scala

...in/scala/spark/scheduler/cluster/ExecutorLossReason.scala

...spark/scheduler/cluster/SparkDeploySchedulerBackend.scala

.../spark/scheduler/cluster/StandaloneSchedulerBackend.scala

...n/scala/spark/scheduler/mesos/MesosSchedulerBackend.scala

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

docs/spark-standalone.md