Add VirtualBox drivers and its modules
Add VirtualBox drivers and its modules

This commit adds VirtualBox modules VirtualBoxPower
and VirtualBoxManagement for managing VMs
through VirtualBox web service.  It also adds two
new drivers pxe_vbox and agent_vbox.

Implements: blueprint ironic-virtualbox-webservice-support
Change-Id: I1e23d21534be30cc4b5a06e998cdce0c5cb04ab6

faizan-barmawer/ironic-lib,citrix-openstack-build/ironic-lib,faizan-barmawer/elytics,NaohiroTamura/ironic-lib,openstack/ironic-lib