This will make a number of things easier in the future, as well as (finally!)
avoiding the Id-smashing problem which has plagued developers for so long.
Boy, I'm glad we're not using sup anymore. This update would have been
insane otherwise.
multicast group memberships. This is not actually operative
at the moment (a lot of other code still needs to be changed), but
this seemed like a useful reference point to check in so that
others (i.e. Bill Fenner) have fair warning of where we are going.
