[SPARK-1780] Non-existent SPARK_DAEMON_OPTS is lurking around

What they really mean is SPARK_DAEMON_***JAVA***_OPTS

Author: Andrew Or <andrewor14@gmail.com>

Closes apache#751 from andrewor14/spark-daemon-opts and squashes the following commits:

70c41f9 [Andrew Or] SPARK_DAEMON_OPTS -> SPARK_DAEMON_JAVA_OPTS

conf/spark-env.sh.template

@@ -39,5 +39,5 @@
 # - SPARK_WORKER_DIR, to set the working directory of worker processes
 # - SPARK_WORKER_OPTS, to set config properties only for the worker (e.g. "-Dx=y")
 # - SPARK_HISTORY_OPTS, to set config properties only for the history server (e.g. "-Dx=y")
-# - SPARK_DAEMON_OPTS, to set config properties for all daemons (e.g. "-Dx=y")
+# - SPARK_DAEMON_JAVA_OPTS, to set config properties for all daemons (e.g. "-Dx=y")
 # - SPARK_PUBLIC_DNS, to set the public dns name of the master or workers

core/src/main/scala/org/apache/spark/SparkConf.scala

@@ -247,7 +247,7 @@ class SparkConf(loadDefaults: Boolean) extends Cloneable with Logging {
           | - ./spark-submit with conf/spark-defaults.conf to set defaults for an application
           | - ./spark-submit with --driver-java-options to set -X options for a driver
           | - spark.executor.extraJavaOptions to set -X options for executors
-          | - SPARK_DAEMON_OPTS to set java options for standalone daemons (i.e. master, worker)
+          | - SPARK_DAEMON_JAVA_OPTS to set java options for standalone daemons (master or worker)
         """.stripMargin
       logError(error)