Link to job UI from standalone deploy cluster web UI

This creates a link from the master to the app UI and should fix [SPARK-802](https://spark-project.atlassian.net/browse/SPARK-802).
![master log](https://f.cloud.github.com/assets/4754931/800743/8a4c8294-ed90-11e2-95b8-af8dcfa79e25.png)