The idea is to try and automatically grab the default gateway and the firewall WAN IP addresses for inclusion in the default HOME_NET and Whitelist.  The old code simply whitelisted the entire WAN subnet, and that was not optimal from a security standpoint.  I am open to better ways to grab the gateways associated with interfaces and then dispense with the idea of WAN being special.  Are there some other pfSense utility functions that could help out?