imaging: add multiple machines with many ethX OK

In profile, when you add multiple machines with many
ethernet cards, display a form with machines list and dropdown
list to choose correct network card.
imaging: Move imaging group from computer to imaging
imaging: Group creation broken
imaging: Fix imaging group creation
imaging: Fix imaging group integration
imaging: integrate imaging activation on profile's creation
dyngroup: display machines who are part of profile in group creation
dyngroup: Move machines to new group

If a machine is already part of a profile, move this to its new profile