Make various things public

## What changes were proposed in this pull request?
This patch is originally authored by vlyubin.

## How was this patch tested?
N/A

Author: Volodymyr Lyubinets <vlyubin@gmail.com>

Closes apache#45 from rxin/rxin-make-various-things-public.

core/src/main/scala/org/apache/spark/api/r/RBackend.scala

@@ -35,7 +35,7 @@ import org.apache.spark.internal.Logging
 /**
  * Netty-based backend server that is used to communicate between R and Java.
  */
-private[spark] class RBackend {
+class RBackend {
 
   private[this] var channelFuture: ChannelFuture = null
   private[this] var bootstrap: ServerBootstrap = null

core/src/main/scala/org/apache/spark/api/r/RRDD.scala

@@ -126,7 +126,7 @@ private[r] object RRDD {
       sparkConf.setExecutorEnv(name.toString, value.toString)
     }
 
-    val jsc = new JavaSparkContext(sparkConf)
+    val jsc = new JavaSparkContext(SparkContext.getOrCreate(sparkConf))
     jars.foreach { jar =>
       jsc.addJar(jar)
     }

repl/scala-2.10/src/main/scala/org/apache/spark/repl/SparkILoop.scala

@@ -71,9 +71,9 @@ class SparkILoop(
   private var in: InteractiveReader = _   // the input stream from which commands come
 
   // NOTE: Exposed in package for testing
-  private[repl] var settings: Settings = _
+  var settings: Settings = _
 
-  private[repl] var intp: SparkIMain = _
+  var intp: SparkIMain = _
 
   @deprecated("Use `intp` instead.", "2.9.0") def interpreter = intp
   @deprecated("Use `intp` instead.", "2.9.0") def interpreter_= (i: SparkIMain): Unit = intp = i
@@ -143,7 +143,7 @@ class SparkILoop(
   protected val originalClassLoader = Utils.getContextOrSparkClassLoader
 
   // classpath entries added via :cp
-  private var addedClasspath: String = ""
+  var addedClasspath: String = ""
 
   /** A reverse list of commands to replay if the user requests a :replay */
   private var replayCommandStack: List[String] = Nil
@@ -738,7 +738,7 @@ class SparkILoop(
     }
   }
 
-  private def addClasspath(arg: String): Unit = {
+  def addClasspath(arg: String): Unit = {
     val f = File(arg).normalize
     if (f.exists) {
       addedClasspath = ClassPath.join(addedClasspath, f.path)

repl/scala-2.10/src/main/scala/org/apache/spark/repl/SparkIMain.scala

@@ -97,7 +97,7 @@ import org.apache.spark.annotation.DeveloperApi
 
     private val SPARK_DEBUG_REPL: Boolean = (System.getenv("SPARK_DEBUG_REPL") == "1")
     /** Local directory to save .class files too */
-    private[repl] val outputDir = {
+    lazy val outputDir = {
       val rootDir = conf.getOption("spark.repl.classdir").getOrElse(Utils.getLocalDir(conf))
       Utils.createTempDir(root = rootDir, namePrefix = "repl")
     }
@@ -206,7 +206,7 @@ import org.apache.spark.annotation.DeveloperApi
 
     // argument is a thunk to execute after init is done
     // NOTE: Exposed to repl package since used by SparkILoop
-    private[repl] def initialize(postInitSignal: => Unit) {
+    def initialize(postInitSignal: => Unit) {
       synchronized {
         if (_isInitialized == null) {
           _isInitialized = io.spawn {
@@ -371,7 +371,7 @@ import org.apache.spark.annotation.DeveloperApi
     def clearExecutionWrapper() = _executionWrapper = ""
 
     /** interpreter settings */
-    private lazy val isettings = new SparkISettings(this)
+    lazy val isettings = new SparkISettings(this)
 
     /**
      * Instantiates a new compiler used by SparkIMain. Overridable to provide
@@ -477,7 +477,7 @@ import org.apache.spark.annotation.DeveloperApi
     }
 
     // NOTE: Exposed to repl package since used by SparkILoop
-    private[repl] def classLoader: AbstractFileClassLoader = {
+    def classLoader: AbstractFileClassLoader = {
       ensureClassLoader()
       _classLoader
     }
@@ -504,11 +504,11 @@ import org.apache.spark.annotation.DeveloperApi
           _runtimeClassLoader
       })
 
-    private def getInterpreterClassLoader() = classLoader
+    def getInterpreterClassLoader() = classLoader
 
     // Set the current Java "context" class loader to this interpreter's class loader
     // NOTE: Exposed to repl package since used by SparkILoopInit
-    private[repl] def setContextClassLoader() = classLoader.setAsContext()
+    def setContextClassLoader() = classLoader.setAsContext()
 
     /**
      * Returns the real name of a class based on its repl-defined name.