Correct path
Split out zero'ing the disk from the cleanup script

This is useful for situations where you may not want to do this in the same
step.
Split out epel into its own script
Move vim setting to cleanup which is run on all platforms
Use epel script
Initial qemu-based openstack image using packer

NOTE: This is using an experimental branch of packer which has support for qemu.
Not quite fully tested yet.