refactor job ui with pool information

core/src/main/scala/spark/SparkContext.scala

core/src/main/scala/spark/scheduler/SparkListener.scala

...main/scala/spark/scheduler/cluster/ClusterScheduler.scala

...scala/spark/scheduler/cluster/ClusterTaskSetManager.scala

.../src/main/scala/spark/scheduler/cluster/Schedulable.scala

...in/scala/spark/scheduler/cluster/SchedulableBuilder.scala

...c/main/scala/spark/scheduler/cluster/SchedulingMode.scala

...c/main/scala/spark/scheduler/cluster/TaskSetManager.scala

...src/main/scala/spark/scheduler/local/LocalScheduler.scala

...ain/scala/spark/scheduler/local/LocalTaskSetManager.scala

core/src/main/scala/spark/ui/UIWorkloadGenerator.scala

core/src/main/scala/spark/ui/jobs/IndexPage.scala

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

core/src/main/scala/spark/ui/jobs/JobProgressUI.scala

core/src/main/scala/spark/ui/jobs/PoolPage.scala

core/src/main/scala/spark/ui/jobs/PoolTable.scala

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