SwitchSnapshot, SwitchSnapshotExtended: fix doc
SwitchSnapshot, SwitchSnapshotExtended: fix doc

Fix and improve the documentation for SwitchSnapshot and
SwitchSnapshotExtended methods. For one thing, move the description
of SwitchSnapshotExtended flags next to those flags.

Signed-off-by: Kir Kolyshkin <c0159612b0ef32139322233232df1a0d189c4b9b@openvz.org>

kolyshkin/goploop