Multicast address allocation service

[Ivan R. Judson]

It occurred to me last night and I mentioned it to tom today; but it's worth
getting in the collective conscious --

It's probably a better idea to have venues ask for addresses through some
single "get new address" method rather than expose via the name whether they
are asking for a random or range address. The venue should never care, it's
just an address. This will also make it easier to encapsulate address
allocation implementations.

--ivan