Refactor batch of issues with Packer/Vagrant box

Refactor batch of issues with Packer/Vagrant box

Use Packer variables to track ODL's version.

Don't require install of ODL Ansible role by user before
Packer build, let Packer manage it (everything should be
tracked in VCS).

Use new CentOS version system and various other minor bug
fixes.

Using a Kludge of ODL's version scheme to hack ODL's
broken versioning scheme into semantic versioning. Vagrant
requires versions of the form X.Y.Z, so we couldn't do
the (ideal) 0.2.3-1 (the last part is *-<package version>).
Since ODL isn't really using the its major version, just
rotating left for now.

Update docs to reflect all changes.

Change-Id: I618fb9b143144dd6019fc44cf9dd66a769df7419
Signed-off-by: Daniel Farrell <dfarrell@redhat.com>