Fix running on yarn documentation
Filter out nulls - prevent NPE
Fix documentation to use yarn-standalone as master
Hope this does not turn into a bike shed change
Updated Scala version in docs generation ruby script.
Fix example jar name
Merge branch 'master' of github.com:mesos/spark
Merge branch 'master' of https://github.com/mridulm/spark
Fixed a couple typos and formating problems in the YARN documentation.
Changed the logging level from info to warning when addJar(null) is
called.