Client/Server Multicast Discovery

[David Blevins]

Been looking into how to do service discovery between client/server  
and server/server.

We've got some code in the client to do failover on a server list but  
by default it really isn't wired up.  It'd be nice to get something in  
so even if we don't support full clustered replication, at the very  
least we could support a bunch of servers that "work together" in a  
stateless fashion.

Looking at adding a new "multicast" server service that just  
advertises the URIs of the other networks services available in the  
system.  We'd probably want it off by default (maybe), but then a  
client could just sort of boot without being pointed to a specific  
server address and theoretically find a server to talk to.

-David