Merge pull request alteryx#111 from kayousterhout/ui_name

Properly display the name of a stage in the UI.

This fixes a bug introduced by the fix for SPARK-940, which
changed the UI to display the RDD name rather than the stage
name. As a result, no name for the stage was shown when
using the Spark shell, which meant that there was no way to
click on the stage to see more details (e.g., the running
tasks). This commit changes the UI back to using the
stage name.

@pwendell -- let me know if this change was intentional

core/src/main/scala/org/apache/spark/scheduler/StageInfo.scala

@@ -33,6 +33,4 @@ class StageInfo(
   val name = stage.name
   val numPartitions = stage.numPartitions
   val numTasks = stage.numTasks
-
-  override def toString = rddName
 }

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

@@ -99,7 +99,7 @@ private[spark] class StageTable(val stages: Seq[StageInfo], val parent: JobProgr
     val poolName = listener.stageIdToPool.get(s.stageId)
 
     val nameLink =
-      <a href={"%s/stages/stage?id=%s".format(UIUtils.prependBaseUri(),s.stageId)}>{s.toString}</a>
+      <a href={"%s/stages/stage?id=%s".format(UIUtils.prependBaseUri(),s.stageId)}>{s.name}</a>
     val description = listener.stageIdToDescription.get(s.stageId)
       .map(d => <div><em>{d}</em></div><div>{nameLink}</div>).getOrElse(nameLink)
     val finishTime = s.completionTime.getOrElse(System.currentTimeMillis())