Convert mac address to use lower case letters

This change simply forces the mac address in 'rhev-template-clone.py' to
use lower case letters. This makes it easier to match up with the
lowercase letters output by the 'arp -n' command.

Signed-off-by: Prakash Surya <surya1@llnl.gov>
Add 'rhev-vm-delete.py' script

Added a new script to automate the process of deleting a VM (the VM will
be stopped if it is currently running). An example usage is below:

    $ ./rhev-vm-delete.py -n VM_NAME

The command will return once the VM has been completely removed.