1:1 streams

It should be possible to insert some sort of an anchor to a key. This will persist across a bunch of nodes, and will serve as a rendezvous point, just as with PassiveRequests. But unlike passive requests, once this has been found, it can be used to create a private, 1:1 channel for messages. This could be used for lossy messages (UDP), lossless messages with retransmission (RDP), or a lossless linear connection (TCP). With this, passive requests, publish/subscribe streams, and ordinary requests, we have all the tools we need to provide an alternative internet, although some things will be much slower on Freenet; certainly shareable data MUST be shared so it can be cached, rather than streamed out to the client on each connection as a normal webserver.