SPARK-1005 Ning upgrade
Made java options to be applied during tests so that they become self explanatory.
Clarify spark.cores.max

It controls the count of cores across the cluster, not on a per-machine basis.
Merge pull request #341 from ash211/patch-5

Clarify spark.cores.max in docs

It controls the count of cores across the cluster, not on a per-machine basis.
Merge pull request #338 from ScrapCodes/ning-upgrade

SPARK-1005 Ning upgrade
Merge pull request #340 from ScrapCodes/sbt-fixes

Made java options to be applied during tests so that they become self explanatory.