Webui improvements.

.gitignore

...es/spark/deploy/master/webui/bootstrap-responsive.min.css

...ain/resources/spark/deploy/master/webui/bootstrap.min.css

...src/main/resources/spark/deploy/master/webui/sorttable.js

...es/spark/deploy/worker/webui/bootstrap-responsive.min.css

...ain/resources/spark/deploy/worker/webui/bootstrap.min.css

core/src/main/resources/spark/deploy/worker/webui/index.html

...src/main/resources/spark/deploy/worker/webui/sorttable.js

core/src/main/scala/spark/deploy/DeployMessage.scala

core/src/main/scala/spark/deploy/master/Master.scala

core/src/main/scala/spark/deploy/master/MasterWebUI.scala

core/src/main/scala/spark/deploy/worker/Worker.scala

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

core/src/main/twirl/common/layout.scala.html

core/src/main/twirl/masterui/index.scala.html

core/src/main/twirl/masterui/job_details.scala.html

core/src/main/twirl/masterui/job_row.scala.html

core/src/main/twirl/masterui/job_table.scala.html

core/src/main/twirl/masterui/worker_row.scala.html

core/src/main/twirl/masterui/worker_table.scala.html