Remove explicit hardcoding of yarn-standalone as args(0) if it is missing.

core/src/hadoop2-yarn/scala/spark/deploy/yarn/ApplicationMaster.scala

@@ -148,22 +148,9 @@ class ApplicationMaster(args: ApplicationMasterArguments, conf: Configuration) e
       .getMethod("main", classOf[Array[String]])
     val t = new Thread {
       override def run() {
-        var mainArgs: Array[String] = null
-        var startIndex = 0
-
-        // I am sure there is a better 'scala' way to do this .... but I am just trying to get things to work right now !
-        if (args.userArgs.isEmpty || args.userArgs.get(0) != "yarn-standalone") {
-          // ensure that first param is ALWAYS "yarn-standalone"
-          mainArgs = new Array[String](args.userArgs.size() + 1)
-          mainArgs.update(0, "yarn-standalone")
-          startIndex = 1
-        }
-        else {
-          mainArgs = new Array[String](args.userArgs.size())
-        }
-
-        args.userArgs.copyToArray(mainArgs, startIndex, args.userArgs.size())
-
+        // Copy
+        var mainArgs: Array[String] = new Array[String](args.userArgs.size())
+        args.userArgs.copyToArray(mainArgs, 0, args.userArgs.size())
         mainMethod.invoke(null, mainArgs)
       }
     }

core/src/hadoop2-yarn/scala/spark/deploy/yarn/ApplicationMasterArguments.scala

@@ -69,7 +69,6 @@ class ApplicationMasterArguments(val args: Array[String]) {
       "  --class CLASS_NAME   Name of your application's main class (required)\n" +
       "  --args ARGS          Arguments to be passed to your application's main class.\n" +
       "                       Mutliple invocations are possible, each will be passed in order.\n" +
-      "                       Note that first argument will ALWAYS be yarn-standalone : will be added if missing.\n" +
       "  --num-workers NUM    Number of workers to start (Default: 2)\n" +
       "  --worker-cores NUM   Number of cores for the workers (Default: 1)\n" +
       "  --worker-memory MEM  Memory per Worker (e.g. 1000M, 2G) (Default: 1G)\n")

core/src/hadoop2-yarn/scala/spark/deploy/yarn/ClientArguments.scala

@@ -92,7 +92,6 @@ class ClientArguments(val args: Array[String]) {
       "  --class CLASS_NAME   Name of your application's main class (required)\n" +
       "  --args ARGS          Arguments to be passed to your application's main class.\n" +
       "                       Mutliple invocations are possible, each will be passed in order.\n" +
-      "                       Note that first argument will ALWAYS be yarn-standalone : will be added if missing.\n" +
       "  --num-workers NUM    Number of workers to start (Default: 2)\n" +
       "  --worker-cores NUM   Number of cores for the workers (Default: 1). This is unsused right now.\n" +
       "  --master-memory MEM  Memory for Master (e.g. 1000M, 2G) (Default: 512 Mb)\n" +