Changed bootstrap colors, fixed logpaging buttons

core/src/main/scala/spark/deploy/worker/ui/WorkerWebUI.scala

@@ -37,7 +37,7 @@ import spark.ui.UIUtils
  */
 private[spark]
 class WorkerWebUI(val worker: Worker, val workDir: File, requestedPort: Option[Int] = None)
-    extends Logging {
+  extends Logging {
   implicit val timeout = Timeout(
     Duration.create(System.getProperty("spark.akka.askTimeout", "10").toLong, "seconds"))
   val host = Utils.localHostName()
@@ -111,23 +111,31 @@ class WorkerWebUI(val worker: Worker, val workDir: File, requestedPort: Option[I
       if (startByte > 0) {
         <a href={"?appId=%s&executorId=%s&logType=%s&offset=%s&byteLength=%s"
           .format(appId, executorId, logType, math.max(startByte-byteLength, 0),
-            byteLength)}>
-          <button>Previous {Utils.memoryBytesToString(math.min(byteLength, startByte))}</button>
+          byteLength)}>
+          <button type="button" class="btn btn-default">
+            Previous {Utils.memoryBytesToString(math.min(byteLength, startByte))}
+          </button>
         </a>
       }
       else {
-        <button disabled="disabled">Previous 0 B</button>
+        <button type="button" class="btn btn-default" disabled="disabled">
+          Previous 0 B
+        </button>
       }
 
     val nextButton =
       if (endByte < logLength) {
         <a href={"?appId=%s&executorId=%s&logType=%s&offset=%s&byteLength=%s".
           format(appId, executorId, logType, endByte, byteLength)}>
-          <button>Next {Utils.memoryBytesToString(math.min(byteLength, logLength-endByte))}</button>
+          <button type="button" class="btn btn-default">
+            Next {Utils.memoryBytesToString(math.min(byteLength, logLength-endByte))}
+          </button>
         </a>
       }
       else {
-        <button disabled="disabled">Next 0 B</button>
+        <button type="button" class="btn btn-default" disabled="disabled">
+          Next 0 B
+        </button>
       }
 
     val content =