Finally got Hadoop working!

The hadoop module is now setup for the hadoop service account.
This includes the Hadoop data and log directory ownership along with
passwordless ssh.

Configured the hadoop module to write logs to /var/log/hadoop.

Added grid management scripts intended to be run by the admin user.
I was thinking about creating some init.d scripts, but will hold off
since systemd appears to be replacing init.d in RHEL 7+.