This commit makes Spark invocation saner by using an assembly JAR to
find all of Spark's dependencies instead of adding all the JARs in
lib_managed. It also packages the examples into an assembly and uses
that as SPARK_EXAMPLES_JAR. Finally, it replaces the old "run" script
with two better-named scripts: "run-examples" for examples, and
"spark-class" for Spark internal classes (e.g. REPL, master, etc). This
is also designed to minimize the confusion people have in trying to use
"run" to run their own classes; it's not meant to do that, but now at
least if they look at it, they can modify run-examples to do a decent
job for them.

As part of this, Bagel's examples are also now properly moved to the
examples package instead of bagel.

Expose `isLocal` in SparkContext.

Hot fix for command runner

Spark on Yarn should use yarn approved directories for spark.local.dir and tmp

Spark on Yarn allow users to specify environment variables 

Pass SBT_OPTS environment through to sbt_launcher

Revert json library change

This reverts commit 1fb1b099, reversing
changes made to c69c4894.

Several Improvements to EC2 Scripts

Fix IDE project generation under SBT

Documentation suggestions for spark streaming.

Create less instances of the random class during ALS initialization.

Re-add removed dependency to fix build under Hadoop 0.23.9

Fixes SBT build under Hadoop 0.23.9 and 2.0.4

Update build docs

Synced sbt and maven builds to use the same dependencies, etc.

Coalesced RDD with locality