Merge pull request #268 from pwendell/shaded-protobuf

Add support for 2.2. to master (via shaded jars)

This patch does a few related things. NOTE: This may not compile correctly for ~24 hours until artifacts fully propagate to Maven Central.

1. Uses shaded versions of akka/protobuf. For more information on how these versions were prepared, see [1].

2. Brings the `new-yarn` project up-to-date with the changes for Akka 2.2.3.

3. Some clean-up of the build now that we don't have to switch akka groups for different YARN versions.

[1]
https://github.com/pwendell/spark-utils/tree/933a309ef85c22643e8e4b5e365652101c4e95de/shaded-protobuf
Reorganize yarn related codes into sub projects to remove duplicate files.
Fix pom for yarn code reorgnaize commit
Change profile name new-yarn to hadoop2.2-yarn
Fix yarn/assemble pom file
Fix pom file for scala binary version
some code clean up for Yarn 2.2
Add README for yarn modules
Fix yarn/README.md and update docs/running-on-yarn.md
Update maven build documentation
A few clean up for yarn 2.0 code