Link the Spark UI to the Yarn UI
fix up minor things
Merge remote-tracking branch 'mesos/master' into yarnUILink

Conflicts:
	core/src/main/scala/org/apache/spark/ui/UIUtils.scala
	core/src/main/scala/org/apache/spark/ui/jobs/PoolTable.scala
	core/src/main/scala/org/apache/spark/ui/jobs/StageTable.scala
	docs/running-on-yarn.md
Review comment changes and update to org.apache packaging
Update based on review comments. Change function to prependBaseUri and fix formatting.
Merge pull request #878 from tgravescs/yarnUILink

Link the Spark UI up to the Yarn UI