Patch from Thomas Graves to improve the YARN Client, and move to more production ready hadoop yarn branch

Fix review comments, add a new api to SparkHadoopUtil to create appropriate Configuration. Modify an example to show how to use SplitInfo

Move back to 2.0.2-alpha, since 2.0.3-alpha is not available in cloudera yet. Also, add netty dependency explicitly to prevent resolving to older 2.3x version. Additionally, comment out retrievePattern to ensure correct netty is picked up

Ensure all ask/await block for spark.akka.askTimeout - so that it is controllable : instead of arbitrary timeouts spread across codebase. In our tests, we use 30 seconds, though default of 10 is maintained

Fudge order of classpath - so that our jars take precedence over what is in CLASSPATH variable. Sounds logical, hope there is no issue cos of it

Fix exception when checkpoint path does not exist (no data in rdd which is being checkpointed for example)

Checkpoint commit - compiles and passes a lot of tests - not all though, looking into FileSuite issues

Checkpoint commit - compiles and passes a lot of tests - not all though, looking into FileSuite issues

Bugfix: WorkerWebUI must respect workDirPath from Worker

Add a shuffle parameter to coalesce.

Move streaming test initialization into 'before' blocks

Don't use deprecated Application in example

Update tuning.md

Make the example more compilable

As of 2.9.0 extending from Application is not recommended

http://www.scala-lang.org/api/2.9.3/index.html#scala.Application

Re-enable deprecation warnings and fix deprecated warning.

Conflicts:
	core/src/test/scala/spark/RDDSuite.scala

Make Executor fields volatile since they're read from the thread pool.

mapWith, flatMapWith and filterWith