Virtualbox USB boot with the Plop boot manager

As virtualbox does not let us natively boot from USB, we need to get creative and use a boot manager that lets us do that anyway.

One such manager is the Plop linux boot manager that takes little less than 600kb of space and provideds floppy, optical drive and usb boot to machines that can't do such things.

Here is the downloand link: http://www.plop.at/en/bootmanager/download.html