We don't have enough config time variables yet, so I added:
FSNODE_IP EXTERNAL_FSNODE_IP which default to ops' IP address if not set. This allows for separate ops/fs nodes, a config Aero has. Also push some IP addresses (boss, ops, fs) into config.h so they can be used in C programs. Specifically tmcd for returning values of "firewall variables" that can be used in default firewall rules. But I will likely wind up putting the var/value pairs in the DB rather than compiling them into tmcd.