cr-restore: set NS_PID environment variable before "post-resume" hook
cr-restore: set NS_PID environment variable before "post-resume" hook

The only one (so far) "post-resume" script needs some pid to join its
namespaces. Let it be containers root.

v4:
1) Enviroonment setup has been was moved to run_scripts
2) Environment variable NS_PID was renamed to CRTOOLS_INIT_PID

Signed-off-by: Stanislav Kinsburskiy <43b28e187c4fe6e53d7ab0bb71957481e322f182@virtuozzo.com>
Signed-off-by: Pavel Emelyanov <c9a32589e048e044184536f7ac71ef92fe82df3e@virtuozzo.com>

KKoukiou/criu-remote,KKoukiou/criu-remote,efiop/criu,efiop/criu,KKoukiou/criu-remote,efiop/criu,eabatalov/criu,KKoukiou/criu-remote,KKoukiou/criu-remote,eabatalov/criu,efiop/criu,eabatalov/criu,eabatalov/criu,efiop/criu,KKoukiou/criu-remote,eabatalov/criu,eabatalov/criu,efiop/criu