vmm/virtualbox: Support VBox 3.1 for new parcels
vmm/virtualbox: Support VBox 3.1 for new parcels

- On VBox 3.1, create the DVD and floppy drives during registration
and delete them on unregistration, since machines with attached drives
cannot be unregistered

- Create IDE and floppy controllers if they are not present when we
attempt to use them, since 3.1 doesn't create these controllers by
default

- Update create_machine(), attach_ide_disk(), and detach_ide_disk()
compat methods for 3.1 syntax

cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr,cmusatyalab/openisr