Add v.v.v/vbox-info to get a map with vbox host's info

This includes virtualbox info (e.g. api version, ws/xpcom, etc.), and
also host info (cpus, memory, O, host network interfaces and their
DHCP config, etc)
Fix IO-APIC for when # CPU > 1. fixes #55

When the HW DSL specifies more than one CPU, the system will
automatically enable :io-apic-enabled?
Add 'nuke' to manager to unconditionally destroy a VM.
Add disk image creation for Hardware DSL.

With this change, when specifying the storage device to attach to a
storage controller, you can define an image to be created.

e.g.  {:device-type :hard-disk
       :location disk-location
       :create? true
       :size disk-in-mb
       :attachment-type :normal}

The presence of :created? (set to true), :location and :size will prompt
the creation of the disk image. Other optional keys are :variants and
:format (see image/create-medium).
Refine support for setting network adapter type (chipset).
Fix issue with destroy after power-down failing sometimes Fixes #56.

destroy will now wait for the VM to be in a lockable state before
attempting to lock. Apparently power-down returns leaving a temporary
lock on the VM, and I can't explain why atm.