BlockManager UI.
code Formatting
Nicer storage level format on RDD page
Merge branch 'master' into blockmanagerUI

Conflicts:
	core/src/main/twirl/spark/deploy/worker/index.scala.html
Merge branch 'master' into blockmanagerUI
Refactor BlockManager UI and adding worker details.
Merge branch 'master' into blockmanagerUI
Merge remote-tracking branch 'dennybritz/blockmanagerUI' into blockmanager_ui

Conflicts:
	core/src/main/scala/spark/RDD.scala
	core/src/main/scala/spark/storage/BlockManagerMaster.scala
	core/src/main/scala/spark/storage/StorageLevel.scala
Make AccumulatorParam an abstract base class.
Fix up some problems from the merge
Merge branch 'master' into blockmanager_ui

Conflicts:
	core/src/main/scala/spark/RDD.scala
Call removeJob instead of killing the cluster.
Handle Master telling the Worker to kill an already-dead executor.
Don't bother creating an exception.
Fix Worker logInfo about unknown executor.
Remove use of abc.ABCMeta due to cloudpickle issue.

cloudpickle runs into issues while pickling subclasses of AccumulatorParam,
which may be related to this Python issue:

    http://bugs.python.org/issue7689

This seems hard to fix and the ABCMeta wasn't necessary, so I removed it.
Added a clearDependencies method in PartitionPruningRDD.
Merge pull request #410 from rxin/splitpruningrdd

Added a clearDependencies method in PartitionPruningRDD.
Add LocalSparkContext to manage common sc variable.
Merge pull request #396 from JoshRosen/spark-653

Make PySpark AccumulatorParam an abstract base class