RFC requires that the DHCP server include the default gateway (0.0.0.0/0) route as part the Classless network list.
Moved to node-setup so it can be set dynamically at setup run time.
fixes AREDN->ticket:155
Makes the nodes advertise using DHCP Options 121 and 249 routes to the mesh (10.0.0.0/8) and the reserved (172.16.0.0/12) address ranges.
This change allows directing systems to prefer the mesh node for mesh ranges unless another network rule is more specific (such as a directly connected network)
This is mostly useful where a PC may have multiple network connections active as it improves the desire for the packets to travel via the mesh network.
Currently the:
10.0.0.0/8 range is used by mesh nodes and dtdlinking of mesh nodes.
172.27.0.0/16 is used for default LAN network on NAT nodes.
172.33.0.0/16 is for ad-hoc tunnels
All others in the advertised range are reserved for future network use.