cgroup: Recreate the same cgroup hierarchy on migration
cgroup: Recreate the same cgroup hierarchy on migration

When live-migrating an OVZ container, recreate the same
CG directories on target as were seen on source.

Real limits will be applied by ovz htype driver after
restore succeeds (TODO)

Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@parallels.com>

xemul/p.haul,xemul/p.haul,xemul/p.haul,avagin/p.haul,jne100/p.haul,aburluka/p.haul,aburluka/p.haul,xemul/p.haul,biddyweb/phaul,marcosnils/p.haul,arthurlockman/p.haul,arthurlockman/p.haul,jne100/p.haul,avagin/p.haul,aburluka/p.haul,aburluka/p.haul,jne100/p.haul,marcosnils/p.haul,biddyweb/phaul,xemul/p.haul,arthurlockman/p.haul,jne100/p.haul,arthurlockman/p.haul,arthurlockman/p.haul,biddyweb/phaul,jne100/p.haul,aburluka/p.haul,avagin/p.haul,marcosnils/p.haul