Merge pull request #396 from pwendell/executor-env

Setting load defaults to true in executor

This preserves the behavior in earlier releases. If properties are set for the executors via `spark-env.sh` on the slaves, then they should take precedence over spark defaults. This is useful for if system administrators are setting properties for a standalone cluster, such as shuffle locations.

/cc @andrewor14 who initially reported this issue.

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

@@ -57,7 +57,7 @@ private[spark] class Executor(
   Utils.setCustomHostname(slaveHostname)
 
   // Set spark.* properties from executor arg
-  val conf = new SparkConf(false)
+  val conf = new SparkConf(true)
   conf.setAll(properties)
 
   // If we are in yarn mode, systems can have different disk layouts so we must set it