Description of problem:
As per customer's request, the config generator  in the ipfailover pod should be able to handle IPv6 addresses as well. Currently, the weight calculation fails.
While the cluster can use IPv6 and as long as no failover happens, everything will work fine. As soon as the failover event happens though, because of said bug the two pods will be in a split brain situation where both believe to be the master.
 - https://github.com/openshift/origin/blob/release-3.7/images/ipfailover/keepalived/lib/config-generators.sh#L238
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Use image on IPv6 network.
2. Cause failover of pods which does not work due to missing IPv6 weight calculation logic.
As of now, Kubernetes does not support IPv6 networks but keepalived supports it as per http://www.keepalived.org/changelog.html.