vrrp: VMAC code cleanup and extensions

Remastered VMAC code. Interface base_ifindex is set by default
to interface ifindex during netlink probe. VMAC interface
base_ifindex is now set during VMAC allocation uppon success
interface creation. Detect if virtual_router_id is declared
after use_mvac keyword is invoked. Add some more log while
setting up and removing VMAC interface.
vrrp: IPv4 & IPv6 multicast group tweaking

Meno Abels extended vrrp framework to support customized
multicast addresses. The address could be set for ipv4 and ipv6
in the global_defs config section using the keywords
vrrp_mcast_group4 and vrrp_mcast_group6.

There are some stupid switches which does a special processing
to 224.0.0.0/8 multicast packets which causes packets drop from
queue overflows in environments which creates 100 and more
multicast control plane packets a second.
vrrp: IPv4 & IPv6 multicast group tweaking doc

Append doc stuff
vrrp: cosmetics

no comments :)
keepalived-1.2.10