[pve-devel] Disks hotplug patchs

[Derumier Alexandre]

Here we go,
virtio disks hot plug patch.

Basicly 

- add hotplug option to vm config file. (if someuse don't want hotplug or os doesn't support it)
- 2 sub (vm_deviceadd/vm_devicedel) for add/remove device with qm monitor command
- 1 sub to parse "info pci" (vm_devices_list), to verify if device is correctly added/remove
- 2 hook to call vm_deviceadd/vm_devicedel, when config file is updated