(cherry picked from commit 401083be9f010f95110a819a49837ecae7d9c4ec)
Signed-off-by: Reynold Xin <rxin@apache.org>

Now, we should use -Pyarn instead of SPARK_YARN when building but README says as follows.

    For Apache Hadoop 2.2.X, 2.1.X, 2.0.X, 0.23.x, Cloudera CDH MRv2, and other Hadoop versions
    with YARN, also set `SPARK_YARN=true`:

      # Apache Hadoop 2.0.5-alpha
      $ sbt/sbt -Dhadoop.version=2.0.5-alpha -Pyarn assembly

      # Cloudera CDH 4.2.0 with MapReduce v2
      $ sbt/sbt -Dhadoop.version=2.0.0-cdh4.2.0 -Pyarn assembly

      # Apache Hadoop 2.2.X and newer
      $ sbt/sbt -Dhadoop.version=2.2.0 -Pyarn assembly

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #1382 from sarutak/SPARK-2457 and squashes the following commits:

e7b2d64 [Kousuke Saruta] Replaced "SPARK_YARN=true" with "-Pyarn" in README

- Look for JARs in the right place
- Launch examples the same way as on Unix
- Load datanucleus JARs if they exist
- Don't attempt to parse local paths as URIs in SparkSubmit, since paths with C:\ are not valid URIs
- Also fixed POM exclusion rules for datanucleus (it wasn't properly excluding it, whereas SBT was)

Author: Matei Zaharia <matei@databricks.com>

Closes #819 from mateiz/win-fixes and squashes the following commits:

d558f96 [Matei Zaharia] Fix comment
228577b [Matei Zaharia] Review comments
d3b71c7 [Matei Zaharia] Properly exclude datanucleus files in Maven assembly
144af84 [Matei Zaharia] Update Windows scripts to match latest binary package layout

Gives a nicely formatted message to the user when `run-example` is run to
tell them to use `spark-submit`.

Author: Patrick Wendell <pwendell@gmail.com>

Closes #704 from pwendell/examples and squashes the following commits:

1996ee8 [Patrick Wendell] Feedback form Andrew
3eb7803 [Patrick Wendell] Suggestions from TD
2474668 [Patrick Wendell] SPARK-1565 (Addendum): Replace `run-example` with `spark-submit`.

Author: Reynold Xin <rxin@apache.org>

Closes #443 from rxin/readme and squashes the following commits:

16853de [Reynold Xin] Updated SBT and Scala instructions.
3ac3ceb [Reynold Xin] README update

Author: Reynold Xin <rxin@apache.org>

Closes #1 from rxin/readme and squashes the following commits:

b3a77cd [Reynold Xin] Removed reference to incubation in README.md.

The link does not work otherwise.

Closes #316

This is misleading because the build doesn't source that file. IMO
it's better to force people to specify build environment variables
on the command line always, like we do in every example.

Changing image references to master branch.

are now needed

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.