Change SVM to use {0,1} labels.
Also add a data validation check to make sure classification labels
are always 0 or 1 and add an appropriate test case.
Fix SVM model and unit test to work with {0,1}.
Also rename validateFuncs to validators.
Specify label format in LogisticRegression.
Adding Linear Regression, and refactoring Ridge Regression.
Centralizing linear data generator and mllib regression tests to use it.
Fixing typos in Java tests, and addressing alignment issues.
Center & scale variables in Ridge, Lasso.
Also add a unit test that checks if ridge regression lowers
cross-validation error.
Add an option to turn off data validation, test it.
Also moves addIntercept to have default true to make it similar
to validateData option
Change to use Yarn appropriate directories rather then /tmp or the user specified spark.local.dir
Throw exception if the yarn local dirs isn't set
Update docs and remove old reference to --user option
Add ability for user to specify environment variables
fix typos
Allow for Executors to have different directories then the Spark Master for Yarn
Updated based on review comments.
Merge pull request #867 from tgravescs/yarnenvconfigs

Spark on Yarn allow users to specify environment variables
Change Executor to only look at the env variable SPARK_YARN_MODE
Merge pull request #865 from tgravescs/fixtmpdir

Spark on Yarn should use yarn approved directories for spark.local.dir and tmp
PySpark: implementing subtractByKey(), subtract() and keyBy()
Don't send SIGINT to Py4J gateway subprocess.

This addresses SPARK-885, a usability issue where PySpark's
Java gateway process would be killed if the user hit ctrl-c.

Note that SIGINT still won't cancel the running s

This fix is based on http://stackoverflow.com/questions/5045771