vzctl set --ipadd/--ipdel: add ability to specify netmasks

This is a preliminary support for specifying netmasks for venet.
It allows to specify a netmask in CIDR notation for IPv4 and IPv6
addresses.

Same IP address with a different netmask is considered to be a separate IP.

This is a work in progress, the next steps are:
* modify all etc/dists/scripts/*{add,del}_ip.sh to understand IP_ADDR
  with netmasks (quite a lot of work)
* document it in vzctl(8) man page (easy)

http://bugzilla.openvz.org/1671
http://bugzilla.openvz.org/1088

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