vmm/virtualbox: Disable USB support in new parcels
vmm/virtualbox: Disable USB support in new parcels

- We currently enable USB support if a parcel is first resumed on a
VirtualBox PUEL system, leading to configuration inconsistencies
between parcels.  USB-enabled parcels suspended on a PUEL system will
refuse to resume on an OSE system and vice versa, causing compatibility
problems between desktop ISR clients and Pocket ISR.  Therefore, disable
USB support in newly-created parcels by default.  Users who want USB
support for particular parcels can enable it by hand using "isr resume
-o noresume <parcel>".

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