Force pseudo-tty allocation in spark-ec2 script.

ssh commands need the -t argument repeated twice if there is no local
tty, e.g. if the process running spark-ec2 uses nohup and the parent
process exits.
Merge pull request #270 from ewencp/really-force-ssh-pseudo-tty-master

Force pseudo-tty allocation in spark-ec2 script.

ssh commands need the -t argument repeated twice if there is no local
tty, e.g. if the process running spark-ec2 uses nohup and the parent
process exits.

Without this change, if you run the script this way (e.g. using nohup from a cron job), it will fail setting up the nodes because some of the ssh commands complain about missing ttys and then fail.

(This version is for the master branch. I've filed a separate request for the 0.8 since changes to the script caused the patches to be different.)
Attempt with extra repositories
Remove trailing slashes from repository specifications.

The correct format is to not have a trailing slash.

For me this caused non-deterministic failures due to issues fetching
certain artifacts. The issue was that some of the maven caches would
fail to fetch the artifact (due to the way that the artifact
path was concatenated with the repository) and this short-circuited
the download process in a silent way. Here is what the log output
looked like:

    Downloading: http://repo.maven.apache.org/maven2/org/spark-project/akka/akka-remote_2.10/2.2.3-shaded-protobuf/akka-remote_2.10-2.2.3-shaded-protobuf.pom
    [WARNING] The POM for org.spark-project.akka:akka-remote_2.10:jar:2.2.3-shaded-protobuf is missing, no dependency information available

This was pretty brutal to debug since there was no error message
anywhere and the path *looks* correct as reported by the Maven log.
Removing extra code in new yarn
Cleanup
Clean-up
One other fix
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