Merge pull request #69 from KarthikTunga/master

Fix for issue SPARK-627. Implementing --config argument in the scripts.

This code fix is for issue SPARK-627. I added code to consider --config arguments in the scripts. In case the  <conf-dir> is not a directory the scripts exit. I removed the --hosts argument. It can be achieved by giving a different config directory. Let me know if an explicit --hosts argument is required.