Vagrant: Add support for parallels and libvirt
Vagrant: Add support for parallels and libvirt

This change adds support for using both parallels and libvirt as the Vagrant
hypervisor backend.

Note this change is untested, but should in theory work. Those running
Vagrant with parallels or libvirt are welcome to try this out.

Change-Id: I23511fec12238a8e3bcccea4874101d9e66c7612
Signed-off-by: Kyle Mestery <9cfbda34e625c7b0454bcb19a48d07c46f9097d2@mestery.com>

openstack/dragonflow,openstack/dragonflow,openstack/dragonflow