node connects with UDP, update the nodes table status with 'up' and the
current time. This is the only thing that can happen when a remote
node connects with UDP (since there is no ssl). The idea is that a
daemon on the remote nodes will wake up periodically and send in a UDP
packet that says its alive. Since the idea is to be low overhead, I'm
using a UDP packet for now, which means I can run it fairly often on
all the clients, without it being too much of a drain. By its nature,
if the remote node can start up tmcc and get a udp packet out, its
probably in good shape. Maybe we will find out this does not work, but
if so I will have lost only "30 minutes". See related changes in
db/node_status.in.

Also, add the code that kicks out remote nodes that connect with tcp
but no ssl (it was commented out while I originally updated the ron
nodes with the new tmcc stuff).