Add runit support
Load the ip_vs kernel module if required

Because of a bug in the Debian Squeeze keepalived package, we
need to load the module by hand or keepalived gets stuck in a loop
trying to load it. See
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=619415
Only reload sysctl settings if they change
Ensure consistent order of IP addresses
Don't write to node attributes in templates