Networking configuration in kickstart templates

extracted from https://github.com/theforeman/foreman/pull/1565
@ekohl so I've tried to pass networking info to anaconda but there's one issue. It does not support alias devices. It results in setting the later IP. What do others think? Should we combine both methods and set aliases (and later bridges) in %post while setting up physical and vlan devices (later probably bonds) through anaconda?