SPARK-724 - Have Akka logging enabled by default for standalone daemons

See the JIRA for more details.

I was only able to test the bash version (don't have Windows)
so maybe check over that the syntax is correct there.
Updating based on code review
Fix passing of superstep in Bagel to avoid seeing new values of the
superstep value upon recomputation, and set the default storage level in
Bagel to MEMORY_AND_DISK
Retry failed ssh commands. This is especially useful during system startup when the hosts may not have yet come on-line but can be useful at other points for people with flakey connections
Just use a loop for retries
Uniform whitespace across scala examples
Fix tests from different projects running in parallel in SBT 0.12
Reversed the order of tests to find a scala executable (in the case when SPARK_LAUNCH_WITH_SCALA is defined): instead of checking in the PATH first, and only then (if not found) for SCALA_HOME, now we check for SCALA_HOME first, and only then (if not defined) do we look in the PATH.  The advantage is that now if the user has a more recent (non-compatible) version of scala in her PATH, she can use SCALA_HOME to point to the older (compatible) version for use with spark.

Suggested by Josh Rosen in this thread:

  https://groups.google.com/forum/?fromgroups=#!topic/spark-users/NC9JKvP8808
Don't pull in old versions of Jackson via hadoop-core
Make ShuffledRDD.prev transient
Increase ReservedCodeCacheSize for sbt
Remove spark-repl's extraneous dependency on spark-streaming
Update Maven build to Scala 2.9.3
Turn on forking in test JVMs to reduce the pressure on perm gen and code
cache sizes due to having 2 instances of the Scala compiler and a bunch
of classloaders.
Merge pull request #576 from jey/update-maven-to-scala-2.9.3

Update Maven build to Scala 2.9.3
Merge pull request #574 from jey/make-repl-not-require-streaming

Remove spark-repl's extraneous dependency on spark-streaming
Update unit test memory to 2 GB
Call commitJob on Hadoop OutputFormats to fix issues with saving on Hadoop 2
Create an empty directory when checkpointing a 0-partition RDD (fixes a
test failure on Hadoop 2.0)
Spark-742: TaskMetrics should not employ per-record timing.

This commit merges together all the changes for purpose of cherry-picking