Test commit karma for Spark git.
Merge remote-tracking branch 'old/master'
Merge remote-tracking branch 'old/master'
Merge remote-tracking branch 'old/master'
Removed repetative import; fixes hidden definition compiler warning.
Adding algorithm for implicit feedback data to ALS
Construct shell commands as sequences for safety and composability
Generate new SSH key for the cluster, make "--identity-file" optional
Remove MemoryStore$Entry.dropPending, unused as of 42e0a68082.
Clarify error messages on SSH failure
Set currentMemory to 0 in clear().
Remove unnecessary entries.get() call.
Start of working on SPARK-615
Make mapPartitionsWithIndex work with JavaRDD's
Merge branch 'master' of https://github.com/mesos/spark
Fix build on ubuntu
Merge branch 'master' of github.com:mesos/spark
Fix issue when local properties pass from parent to child thread
Fix issue with spark_ec2 seeing empty security groups

Under unknown, but occasional, circumstances, reservation.groups is empty
despite reservation.instances each having groups. This means that the
spark_ec2 get_existing_clusters() method would fail to find any instances.
To fix it, we simply use the instances' groups as the source of truth.

Note that this is actually just a revival of PR #827, now that the issue
has been reproduced.
Merge pull request #938 from ilikerps/master

Fix issue with spark_ec2 seeing empty security groups
After unit tests, clear port properties unconditionally

In MapOutputTrackerSuite, the "remote fetch" test sets spark.driver.port
and spark.hostPort, assuming that they will be cleared by
LocalSparkContext. However, the test never sets sc, so it remains null,
causing LocalSparkContext to skip clearing these properties. Subsequent
tests therefore fail with java.net.BindException: "Address already in
use".

This commit makes LocalSparkContext clear the properties even if sc is
null.