[SPARK-5732][CORE]:Add an option to print the spark version in spark script.

Naturally, we may need to add an option to print the spark version in spark script. It is pretty common in script tool.
![9](https://cloud.githubusercontent.com/assets/7402327/6183331/cab1b74e-b38e-11e4-9daa-e26e6015cff3.JPG)

Author: uncleGen <hustyugm@gmail.com>
Author: genmao.ygm <genmao.ygm@alibaba-inc.com>

Closes #4522 from uncleGen/master-clean-150211 and squashes the following commits:

9f2127c [genmao.ygm] revert the behavior of "-v"
015ddee [uncleGen] minor changes
463f02c [uncleGen] minor changes

core/src/main/scala/org/apache/spark/deploy/SparkSubmit.scala

@@ -37,6 +37,7 @@ import org.apache.ivy.core.settings.IvySettings
 import org.apache.ivy.plugins.matcher.GlobPatternMatcher
 import org.apache.ivy.plugins.resolver.{ChainResolver, IBiblioResolver}
 
+import org.apache.spark.SPARK_VERSION
 import org.apache.spark.deploy.rest._
 import org.apache.spark.executor._
 import org.apache.spark.util.{ChildFirstURLClassLoader, MutableURLClassLoader, Utils}
@@ -83,14 +84,25 @@ object SparkSubmit {
   // Exposed for testing
   private[spark] var exitFn: () => Unit = () => System.exit(1)
   private[spark] var printStream: PrintStream = System.err
-  private[spark] def printWarning(str: String) = printStream.println("Warning: " + str)
-  private[spark] def printErrorAndExit(str: String) = {
+  private[spark] def printWarning(str: String): Unit = printStream.println("Warning: " + str)
+  private[spark] def printErrorAndExit(str: String): Unit = {
     printStream.println("Error: " + str)
     printStream.println("Run with --help for usage help or --verbose for debug output")
     exitFn()
   }
+  private[spark] def printVersionAndExit(): Unit = {
+    printStream.println("""Welcome to
+      ____              __
+     / __/__  ___ _____/ /__
+    _\ \/ _ \/ _ `/ __/  '_/
+   /___/ .__/\_,_/_/ /_/\_\   version %s
+      /_/
+                        """.format(SPARK_VERSION))
+    printStream.println("Type --help for more information.")
+    exitFn()
+  }
 
-  def main(args: Array[String]) {
+  def main(args: Array[String]): Unit = {
     val appArgs = new SparkSubmitArguments(args)
     if (appArgs.verbose) {
       printStream.println(appArgs)

core/src/main/scala/org/apache/spark/deploy/SparkSubmitArguments.scala

@@ -417,6 +417,9 @@ private[spark] class SparkSubmitArguments(args: Seq[String], env: Map[String, St
         verbose = true
         parse(tail)
 
+      case ("--version") :: tail =>
+        SparkSubmit.printVersionAndExit()
+
       case EQ_SEPARATED_OPT(opt, value) :: tail =>
         parse(opt :: value :: tail)
 
@@ -485,6 +488,7 @@ private[spark] class SparkSubmitArguments(args: Seq[String], env: Map[String, St
         |
         |  --help, -h                  Show this help message and exit
         |  --verbose, -v               Print additional debug output
+        |  --version,                  Print the version of current Spark
         |
         | Spark standalone with cluster deploy mode only:
         |  --driver-cores NUM          Cores for driver (Default: 1).