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.