Fix to Stage UI to display numbers on progress bar

Fixes an issue on Stage UI to display numbers on progress bar which are today hidden behind the progress bar div. Please refer to the attached images to see the issue.
![screen shot 2014-03-21 at 4 48 46 pm](https://f.cloud.github.com/assets/563652/2489083/8c127e80-b153-11e3-807c-048ebd45104b.png)
![screen shot 2014-03-21 at 4 49 00 pm](https://f.cloud.github.com/assets/563652/2489084/8c12cf5c-b153-11e3-8747-9d93ff6fceb4.png)

Author: Emtiaz Ahmed <[email protected]>

Closes #201 from emtiazahmed/master and squashes the following commits:

a7964fe [Emtiaz Ahmed] Fix to Stage UI to display numbers on progress bar

Author: emtiazahmed

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

@@ -63,7 +63,7 @@ private[ui] class StageTable(stages: Seq[StageInfo], parent: JobProgressUI) {
     val startWidth = "width: %s%%".format((started.toDouble/total)*100)
 
     <div class="progress">
-      <span style="text-align:center; position:absolute; width:100%;">
+      <span style="text-align:center; position:absolute; width:100%; left:0;">
         {completed}/{total} {failed}
       </span>
       <div class="bar bar-completed" style={completeWidth}></div>