Fixed SPARK-795 with explicit dependencies

Remove some stack traces from sbt test output

Added "Labeled" to util functions for labeled data

Make binSearch method tail-recursive for RidgeRegression

1. Set akka log level to ERROR before shutting down the actorSystem.
This avoids akka log messages (like Spray) from falling back to INFO
on the Stdout logger
2. Initialize netty to use SLF4J in LocalSparkContext. This ensures that
stack trace thrown during shutdown is handled by SLF4J instead of stdout

update guava version from 11.0.1 to 14.0.1

If a task fails before the metrics are initialized, it remains possible
that the metrics field will be `None`. This patch accounts for that possbility
by keeping metrics as an `Option` at all times.

Use standard ASF published avro module instead of a proprietory built one

Conflicts:
	core/src/main/scala/spark/scheduler/DAGScheduler.scala
	core/src/main/scala/spark/util/AkkaUtils.scala
	pom.xml

Add support for running Spark on Yarn on a secure Hadoop Cluster

s/ActorSystemImpl/ExtendedActorSystem/ as ActorSystemImpl results in a warning

Add config template file for fair scheduler feature

Bug fix: SPARK-789

Remove active job from idToActiveJob when job finished or aborted

Fixed major performance bug in Network Receiver

Start of ML package