[RFC][PATCH 7/7][v2] Define clone_with_pids syscall

[Sukadev Bhattiprolu]

Serge E. Hallyn [serge at hallyn.com] wrote:
| 
| If a container at pidns level 2, with 1 more pidns underneath it,
| is checkpointed, then the checkpoint image should only reflect
| the base and child pidns.  The two ancestor pidns levels should
| not be there.

Agree. I meant to say that we would need to specify more than 2
pids when checkpoint/restarting apps with deeply nested namespaces
if any :-)

Specifying bottom-up may solve the problem I guess.