Suggested small changes to Java code for slightly more standard style, encapsulation and in some cases performance
Fix handling of empty SPARK_EXAMPLES_JAR
Add a script to download sbt if not present on the system
Pass commands down to system sbt as well
Switch from sbt to ./sbt in the README file
Spelling
Make sbt in the sbt directory
And update docs to match
reindent
Removing SPARK_EXAMPLES_JAR in the code
Quite akka when remote lifecycle logging is disabled.

I noticed when connecting to a standalone cluster Spark gives a bunch
of Akka ERROR logs that make it seem like something is failing.

This patch does two things:

1. Akka dead letter logging is turned on/off according to the existing
   lifecycle spark property.
2. We explicitly silence akka's EndpointWriter log in log4j. This is necessary
   because for some reason that log doesn't pick up on the lifecycle
   logging settings. After a few hours of debugging this was the only solution
   I found that worked.
Provide logging when attempts to connect to the master fail.

Without these it's a bit less clear what's going on for the user.

One thing I realize when doing this is that akka itself actually retries
the initial association. So the retry we currently have is redundant with
akka's.
Fall back to zero-arg constructor for Serializer initialization if there is no constructor that accepts SparkConf.
This maintains backward compatibility with older serializers implemented by users.
Merge pull request #335 from rxin/ser

Fall back to zero-arg constructor for Serializer initialization if there is no constructor that accepts SparkConf.

This maintains backward compatibility with older serializers implemented by users.
Merge pull request #334 from pwendell/examples-fix

Removing SPARK_EXAMPLES_JAR in the code

This re-writes all of the examples to use the `SparkContext.jarOfClass` mechanism for loading the examples jar. This necessary for environments like YARN and the Standalone mode where example programs will be submit from inside the cluster rather than at the client using `./spark-example`.

This still leaves SPARK_EXAMPLES_JAR in place in the shell scripts for setting up the classpath if `./spark-example` is run.
Responding to Aaron's review
Code review feedback
Fix indentatation
Finish documentation changes
Merge pull request #333 from pwendell/logging-silence

Quiet ERROR-level Akka Logs

This fixes an issue I've seen where akka logs a bunch of things at ERROR level when connecting to a standalone cluster, even in the normal case. I noticed that even when lifecycle logging was disabled, the netty code inside of akka still logged away via akka's EndpointWriter class. There are also some other log streams that I think are new in akka 2.2.1 that I've disabled.

Finally, I added some better logging to the standalone client. This makes it more clear when a connection failure occurs what is going on. Previously it never explicitly said if a connection attempt had failed.

The commit messages here have some more detail.