* 'master' of github.com:tailscale/tailscale:
netcheck: fix data races for staggler STUN packets arriving after GetReport
wgengine/magicsock: add a pointer value for logging
netcheck: ignore IPv4 STUN failures if we saw at least one reply
netcheck: ignore IPv6 STUN failures
derp: add clients_replaced counter
version: bump OSS version datestamp.
relaynode itself is not long for this world, deprecated in favour of
tailscale/tailscaled. But now that the control server supports central
distribution of packet filters, let's actually take advantage of it in
a final, backward compatible release of relaynode.