Merge branch 'master' of https://github.com/mesos/spark
Minor style fixes
Increasing inter job arrival
Slight refactoring to SparkContext functions
Minor refactoring and code cleanup
Adding application-level metrics.

This adds metrics for applications in the deploy Master.
Small style fix
under_scores --> camelCase for config options
Improving documentation in config file example
Merge branch 'master' of https://github.com/mesos/spark
Merge pull request #768 from pwendell/pr-695

Minor clean-up of fair scheduler UI
Merge pull request #743 from pwendell/app-metrics

Add application metrics to standalone master
Shows time the app has been running
Increase Kryo buffer size in ALS since some arrays become big
Merge pull request #772 from karenfeng/ui-843

Show app duration
Only reduce the number of cores once when removing an executor
Timeout zombie workers
milliseconds -> seconds in timeOutDeadWorkers logging
Moved handling of timed out workers within the Master actor