vzmigrate: fix for --snapshot

Apparently, option -s|--snapshot (added in commit 85d5266) was not
working properly (or at all). The problem is top_delta (the one
to be excluded from rsync and migrated using ploop copy) was determined
before the snapshot is done.

Fix by moving get_ploop_info() call to right after vzctl snapshot.
The only downside is if ploop proc is weird and get_ploop_info() fails,
there is more to rollback. As it shouldn't happen regularly, we don't
care much about longer rollback.

https://bugzilla.openvz.org/2907

Reported-by: Pavel Odintsov <pavel.odintsov@gmail.com>
Signed-off-by: Kir Kolyshkin <kir@openvz.org>
init.d/vz-redhat: show CT stop status

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
init.d/vz-redhat: implement parallel CT start

Implemented in a way similar to parallel CT stop.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
init.d/vz, vz.conf: use/expose VE_PARALLEL

Parallelism of VE start/stop in vz initscript was calculated
as number of CPUs * 4. It makes sense to give a user an ability
to change the number, so let's name it VE_PARALLEL and put to
global vz.conf file. If unset, it is still autocalculated the same way.

vz.conf(5) man page modified accordingly

Parameter name added into "well known" ones in src/lib/config.c
to avoid a warning from vzctl.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
init.d/vz-gentoo: show CT stop status

Similar to the commit 3a14155.

Signed-off-by: Kir Kolyshkin <kir@openvz.org>
init.d/vz-gentoo: implement parallel CT start

Similar to commit d9f78ac. Not tested :(

Signed-off-by: Kir Kolyshkin <kir@openvz.org>