New features/dynamips-kernel-datapath.md: the anchor model (persistent TAP
per Ethernet port, the hypervisor opens it with nio create_tap), port
selection via the adapter registry, the anchor lifecycle with QEMU's stop
order and the stop-is-not-close semantics, link operations, capture/
markers/filters, the relay fallback, the live e2e results, configuration
and the roadmap (Ethernet switch next). The IOU and QEMU roadmaps note
that Dynamips has landed.
