Fix Cygwin support in several scripts.

This allows the spark-shell, spark-class, run-example, make-distribution.sh,
and ./bin/start-* scripts to work under Cygwin.  Note that this doesn't
support PySpark under Cygwin, since that requires many additional `cygpath`
calls from within Python and will be non-trivial to implement.

This PR was inspired by, and subsumes, #253 (so close #253 after this is merged).
Merge pull request #265 from markhamstra/scala.binary.version

DRY out the POMs with scala.binary.version

...instead of hard-coding 2.10 repeatedly.

As long as it's not a `<project>`-level `<artifactId>`, I think that we are okay parameterizing these.
SVD++ demo
Merge branch 'master' of git://github.com/apache/incubator-spark
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.
Track task value serialisation time in TaskMetrics.
UI to display serialisation time of a stage.
Merge pull request #245 from gregakespret/task-maxfailures-fix

Fix for spark.task.maxFailures not enforced correctly.

Docs at http://spark.incubator.apache.org/docs/latest/configuration.html say:

```
spark.task.maxFailures

Number of individual task failures before giving up on the job. Should be greater than or equal to 1. Number of allowed retries = this value - 1.
```

Previous implementation worked incorrectly. When for example `spark.task.maxFailures` was set to 1, the job was aborted only after the second task failure, not after the first one.
Merge pull request #94 from ankurdave/load-edges-columnar

Load edges in columnar format
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.)
Merge remote-tracking branch 'upstream/master' into mrTriplets-active-set

Conflicts:
	graph/src/main/scala/org/apache/spark/graph/impl/GraphImpl.scala
Merge pull request #100 from ankurdave/mrTriplets-active-set

Support activeSet option in mapReduceTriplets
Add clustered index on edges by source vertex

This allows efficient edge scan in mapReduceTriplets when many source
vertices are inactive. The scan method switches from edge scan to
clustered index scan when less than 80% of source vertices are active.
Incorporate pwendell's code review suggestions.
Merge branch 'master' of git://github.com/apache/incubator-spark
Missed a spot; had an objectSer here too.
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