Initial commit of adding histogram functionality to the DoubleRDDFunctions.
Add tests for the Java implementation.
CR feedback
Remove extranious type definitions from inside of tests
Remove extranious type declerations
Add graphite sink for metrics

This adds a metrics sink for graphite.  The sink must
be configured with the host and port of a graphite node
and optionally may be configured with a prefix that will
be prepended to all metrics that are sent to graphite.
Cleanup GraphiteSink.scala based on feedback

* Reorder imports according to the style guide
* Consistently use propertyToOption in all places
XORShift RNG with unit tests and benchmark
To run unit test, start SBT console and type:
compile
test-only org.apache.spark.util.XORShiftRandomSuite
To run benchmark, type:
project core
console
Once the Scala console starts, type:
org.apache.spark.util.XORShiftRandom.benchmark(100000000)
Updates to reflect pull request code review
Remove explicit boxing
Add spaces
Formatting and scoping (private[spark]) updates
Make XORShiftRandom explicit in KMeans and roll it back for RDD
Fix Kryo Serializer buffer inconsistency

The documentation here is inconsistent with the coded default and other documentation.
TimeTrackingOutputStream should pass on calls to close() and flush().

Without this fix you get a huge number of open shuffles after running
shuffles.
Add YarnClientClusterScheduler and Backend.

With this scheduler, the user application is launched locally,
While the executor will be launched by YARN on remote nodes.

This enables spark-shell to run upon YARN.
Merge pull request #196 from pwendell/master

TimeTrackingOutputStream should pass on calls to close() and flush().

Without this fix you get a huge number of open files when running shuffles.
Merge pull request #193 from aoiwelle/patch-1

Fix Kryo Serializer buffer documentation inconsistency

The documentation here is inconsistent with the coded default and other documentation.
Fix 'timeWriting' stat for shuffle files

Due to concurrent git branches, changes from shuffle file consolidation patch
caused the shuffle write timing patch to no longer actually measure the time,
since it requires time be measured after the stream has been closed.
Support preservesPartitioning in RDD.zipPartitions