If the prefixlength of an IPv6 VRRP VIP is 128, add the VIP as a depreca...

...ted address so Linux won't use it as a source address. If the prefixlength is other than 128, allow it to be used as a sourceaddress

Basically copied from http://marc.info/?l=keepalived-devel&m=130200733315039, by Leo Baltus.

Please note that I normally do not code anything else than Perl/Python/Shell. Commit does work as intended though.