Avoid stalls when computation of cached RDD throws exception

Raise exception when hashing Java arrays (SPARK-597)

Improved jekyll and scala docs. Made many classes and method private to remove them from scala docs.

Fix deletion of files in current working directory by clearFiles()

This fixes an issue where Spark could delete
original files in the current working directory
that were added to the job using addFile().

There was also the potential for addFile() to
overwrite local files, which is addressed by
changing Utils.fetchFile() to log a warning
instead of overwriting a file with new contents.

This is a short-term fix; a better long-term
solution would be to remove the dependence on
storing files in the current working directory,
since we can't change the cwd from Java.

Modifications to make sure LocalScheduler terminate cleanly without errors when SparkContext is shutdown, to minimize spurious exception during master failure tests.

Conflicts:
	core/src/main/scala/spark/ParallelCollection.scala
	core/src/main/scala/spark/RDD.scala
	core/src/main/scala/spark/rdd/BlockRDD.scala
	core/src/main/scala/spark/rdd/CartesianRDD.scala
	core/src/main/scala/spark/rdd/CoGroupedRDD.scala
	core/src/main/scala/spark/rdd/CoalescedRDD.scala
	core/src/main/scala/spark/rdd/FilteredRDD.scala
	core/src/main/scala/spark/rdd/FlatMappedRDD.scala
	core/src/main/scala/spark/rdd/GlommedRDD.scala
	core/src/main/scala/spark/rdd/HadoopRDD.scala
	core/src/main/scala/spark/rdd/MapPartitionsRDD.scala
	core/src/main/scala/spark/rdd/MapPartitionsWithSplitRDD.scala
	core/src/main/scala/spark/rdd/MappedRDD.scala
	core/src/main/scala/spark/rdd/PipedRDD.scala
	core/src/main/scala/spark/rdd/SampledRDD.scala
	core/src/main/scala/spark/rdd/ShuffledRDD.scala
	core/src/main/scala/spark/rdd/UnionRDD.scala
	core/src/main/scala/spark/scheduler/ResultTask.scala
	core/src/test/scala/spark/CheckpointSuite.scala

lookup() needn't fail when there is no partitioner

Allow distinct() to be called without parentheses

Kryo2 update against Spark master

Conflicts:
	core/src/main/scala/spark/MapOutputTracker.scala
	core/src/main/scala/spark/PairRDDFunctions.scala
	core/src/main/scala/spark/ParallelCollection.scala
	core/src/main/scala/spark/RDD.scala
	core/src/main/scala/spark/rdd/BlockRDD.scala
	core/src/main/scala/spark/rdd/CartesianRDD.scala
	core/src/main/scala/spark/rdd/CoGroupedRDD.scala
	core/src/main/scala/spark/rdd/CoalescedRDD.scala
	core/src/main/scala/spark/rdd/FilteredRDD.scala
	core/src/main/scala/spark/rdd/FlatMappedRDD.scala
	core/src/main/scala/spark/rdd/GlommedRDD.scala
	core/src/main/scala/spark/rdd/HadoopRDD.scala
	core/src/main/scala/spark/rdd/MapPartitionsRDD.scala
	core/src/main/scala/spark/rdd/MapPartitionsWithSplitRDD.scala
	core/src/main/scala/spark/rdd/MappedRDD.scala
	core/src/main/scala/spark/rdd/PipedRDD.scala
	core/src/main/scala/spark/rdd/SampledRDD.scala
	core/src/main/scala/spark/rdd/ShuffledRDD.scala
	core/src/main/scala/spark/rdd/UnionRDD.scala
	core/src/main/scala/spark/storage/BlockManager.scala
	core/src/main/scala/spark/storage/BlockManagerId.scala
	core/src/main/scala/spark/storage/BlockManagerMaster.scala
	core/src/main/scala/spark/storage/StorageLevel.scala
	core/src/main/scala/spark/util/MetadataCleaner.scala
	core/src/main/scala/spark/util/TimeStampedHashMap.scala
	core/src/test/scala/spark/storage/BlockManagerSuite.scala
	run

Conflicts:
	core/src/main/scala/spark/ParallelCollection.scala
	core/src/test/scala/spark/CheckpointSuite.scala
	streaming/src/main/scala/spark/streaming/DStream.scala

Added the ability in block manager to remove blocks.

SPARK-616: Logging dead workers in Web UI.

excessive debug messages.

Tweaked debian packaging to be a bit more in line with debian standards

Fixed repl maven build