Add support for Spark on Yarn on a secure Hadoop cluster
upmerge with latest mesos/spark master and fix hbase compile with hadoop2-yarn profile
Partially working checkpoint
Completely hacked version of block manager UI in jetty
Minor cleanup
Adding deterministic port
Fix in storage status page
Spray refactoring for master web UI
Commenting unfinished part
Adding WebUI file
Cleaning up master web UI
Some comments
Adding worker version of UI
Changing JSON protocol and removing spray code
Some JSON cleanup
Removing dead code
Updating Maven build
Removing twirl files
Import cleanup
Refactoring UI packages