[SPARK-20421][core] Mark internal listeners as deprecated.

These listeners weren't really meant for external consumption, but they're
public and marked with @DeveloperAPI. Adding the deprecated tag warns people
that they may soon go away (as they will as part of the work for SPARK-18085.

Note that not all types made public by #648
are being deprecated. Some remaining types are still exposed through the
SparkListener API.

Also note the text for StorageStatus is a tiny bit different, since I'm not
so sure I'll be able to remove it. But the effect for the users should be the
same (they should stop trying to use it).

core/src/main/scala/org/apache/spark/storage/StorageStatusListener.scala

@@ -30,6 +30,7 @@ import org.apache.spark.scheduler._
  * This class is thread-safe (unlike JobProgressListener)
  */
 @DeveloperApi
+@deprecated("This class will be removed in a future release.", "2.2.0")
 class StorageStatusListener(conf: SparkConf) extends SparkListener {
   // This maintains only blocks that are cached (i.e. storage level is not StorageLevel.NONE)
   private[storage] val executorIdToStorageStatus = mutable.Map[String, StorageStatus]()

core/src/main/scala/org/apache/spark/storage/StorageUtils.scala

@@ -35,6 +35,7 @@ import org.apache.spark.internal.Logging
  * class cannot mutate the source of the information. Accesses are not thread-safe.
  */
 @DeveloperApi
+@deprecated("This class may be removed or made private in a future release.", "2.2.0")
 class StorageStatus(
     val blockManagerId: BlockManagerId,
     val maxMemory: Long,

core/src/main/scala/org/apache/spark/ui/env/EnvironmentTab.scala

@@ -32,6 +32,7 @@ private[ui] class EnvironmentTab(parent: SparkUI) extends SparkUITab(parent, "en
  * A SparkListener that prepares information to be displayed on the EnvironmentTab
  */
 @DeveloperApi
+@deprecated("This class will be removed in a future release.", "2.2.0")
 class EnvironmentListener extends SparkListener {
   var jvmInformation = Seq[(String, String)]()
   var sparkProperties = Seq[(String, String)]()

core/src/main/scala/org/apache/spark/ui/exec/ExecutorsTab.scala

@@ -62,6 +62,7 @@ private[ui] case class ExecutorTaskSummary(
  * A SparkListener that prepares information to be displayed on the ExecutorsTab
  */
 @DeveloperApi
+@deprecated("This class will be removed in a future release.", "2.2.0")
 class ExecutorsListener(storageStatusListener: StorageStatusListener, conf: SparkConf)
     extends SparkListener {
   val executorToTaskSummary = LinkedHashMap[String, ExecutorTaskSummary]()

core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala

@@ -41,6 +41,7 @@ import org.apache.spark.ui.jobs.UIData._
  * updating the internal data structures concurrently.
  */
 @DeveloperApi
+@deprecated("This class will be removed in a future release.", "2.2.0")
 class JobProgressListener(conf: SparkConf) extends SparkListener with Logging {
 
   // Define a handful of type aliases so that data structures' types can serve as documentation.

core/src/main/scala/org/apache/spark/ui/storage/StorageTab.scala

@@ -39,6 +39,7 @@ private[ui] class StorageTab(parent: SparkUI) extends SparkUITab(parent, "storag
  * This class is thread-safe (unlike JobProgressListener)
  */
 @DeveloperApi
+@deprecated("This class will be removed in a future release.", "2.2.0")
 class StorageListener(storageStatusListener: StorageStatusListener) extends BlockStatusListener {
 
   private[ui] val _rddInfoMap = mutable.Map[Int, RDDInfo]() // exposed for testing